An unsubscribe link is a visible link in a marketing email that lets a recipient opt out of future promotional messages from a sender. Usually placed in the footer, it should be easy to find, work without friction, and update the sender’s suppression records so the recipient no longer receives the marketing email categories they chose to leave.

What is an unsubscribe link?

An unsubscribe link is the recipient-facing part of an email opt-out system. It gives someone who no longer wants newsletters, promotional offers, product announcements, or other marketing emails a direct route to stop them.

In its simplest form, the link appears near the bottom of an email with language such as:

  • Unsubscribe
  • Stop receiving these emails
  • Manage email preferences
  • Update your subscription settings

The destination may immediately remove the person from a list, show a confirmation page, or open a preference center where they can reduce frequency or select the topics they still want. What matters is that the person can make a meaningful opt-out choice quickly and that the sender reliably honors it.

An unsubscribe link is not the same thing as a reply asking to be removed, a contact form, or a support ticket. Those routes can be useful as backups, but a marketing recipient should not have to compose an email, sign in, remember a password, call support, or explain why they are leaving just to stop promotional mail.

For campaign email, the footer link is the familiar implementation. Mailbox providers can also expose a native unsubscribe control in their interface when a sender publishes the appropriate message headers. That header-based experience is commonly called one-click unsubscribe, but it complements rather than replaces a visible unsubscribe link in the message body.

Why an unsubscribe link matters for deliverability

A working unsubscribe link is a safety valve for recipients and a reputation control for senders. Someone who has lost interest has several possible actions: ignore the email, delete it, complain about it as spam, or unsubscribe. The sender should make the last option the easiest one.

Spam complaints are stronger negative signals than ordinary disengagement. A person who marks a campaign as spam is telling their mailbox provider that the mail was unwanted or misleading. That can affect future inbox placement for the sending domain and, depending on the sending setup, for shared or dedicated IP reputation as well.

By contrast, an unsubscribe is usually an explicit preference signal. It reduces the size of the reachable marketing audience, but it also removes an unengaged recipient who might otherwise complain, continue ignoring campaigns, or become an invalid address later. Losing a subscriber who does not want the messages is often healthier than keeping a larger list with weak permission and poor engagement.

It gives recipients a better alternative to the spam button

Recipients rarely think in terms of sender reputation. They simply want unwanted mail to stop. If the unsubscribe route is hidden, broken, slow, or confusing, the spam button is available in nearly every inbox and takes only a moment to use.

A clear footer link changes that decision path. It says: this sender recognizes that preferences change and offers a straightforward way out. That does not guarantee a recipient will never complain, especially if the original signup was unclear, but it removes a common source of frustration.

It supports mailbox-provider expectations

Major mailbox providers expect bulk marketing senders to make opt-out easy. Gmail’s sender guidelines require senders that send more than 5,000 messages per day to Gmail accounts to support one-click unsubscribe for marketing and subscribed messages, alongside authentication and other requirements. The threshold is about sending volume to Gmail recipients, not merely the size of a sender’s total database.

The practical lesson applies below that threshold too: do not treat easy unsubscribing as a feature needed only after a list becomes large. A scalable sending program should build clean opt-out handling from its first campaign. Retrofitting suppression behavior after volume grows can create inconsistencies across products, regions, sending tools, and customer records.

It protects campaign performance data

Keeping people on a list after they want to leave makes campaign reporting less useful. They may stop opening, stop clicking, report messages as spam, or create noise in engagement analysis. A high total recipient count can look impressive while masking an audience that is increasingly uninterested.

A clean opt-out process makes the active list more representative of people who still want the relationship. That improves the interpretability of engagement trends. It also gives lifecycle and marketing teams a more honest view of which content, frequency, acquisition source, or audience segment is causing people to disengage.

It is part of compliance, not merely a conversion decision

Requirements vary by jurisdiction and message type, so a sender should get legal advice for its specific program. In the United States, the CAN-SPAM Act requires commercial messages to provide a clear and conspicuous explanation of how recipients can opt out of future marketing email. The Federal Trade Commission also says senders may offer category-level options, but must include a way to stop all marketing messages from the sender.

This has an important operational implication: the preference center cannot be a maze designed to preserve subscriptions at all costs. It can offer useful choices, such as fewer messages or fewer categories, but it must still allow a recipient to stop marketing mail.

Unsubscribe link vs. unsubscribe rate vs. one-click unsubscribe

These terms are related but describe different parts of an email program. Mixing them up can lead to faulty reporting or incomplete technical implementations.

The unsubscribe link

The unsubscribe link is the visible element in the email body. It is typically an HTML anchor in the footer, though it should also have a plain-text equivalent when a plain-text MIME part is sent.

A recipient clicks it, and the sender’s opt-out flow begins. The URL normally includes an opaque, recipient-specific token or another secure identifier that lets the system know whose preferences to update without exposing their email address in the URL.

The unsubscribe rate

The unsubscribe rate is a campaign metric. It describes how many delivered messages resulted in an unsubscribe during the reporting window.

A common formula is:

Unsubscribe rate = unique unsubscribes / delivered emails × 100

Suppose a campaign is sent to 50,000 recipients. Of those messages, 49,000 are delivered, and 147 unique recipients unsubscribe. The unsubscribe rate is:

147 / 49,000 × 100 = 0.30%

The rate is based on delivered email rather than attempted sends because undelivered messages did not give recipients a usable opportunity to opt out. Use unique unsubscribe events when possible; one person clicking an unsubscribe link three times should not count as three people leaving.

Treat this metric carefully. A low unsubscribe rate is not automatically a success. It may reflect strong relevance and permission, but it can also happen when the link is hard to find, the page fails, the user is forced to log in, or recipients choose spam complaints instead. Compare unsubscribe rate with spam complaints, click behavior, delivery failures, acquisition sources, and message frequency.

One-click unsubscribe

One-click unsubscribe is a header-based capability that enables a mailbox provider to offer its own unsubscribe interface near the sender details. It is defined by RFC 8058 and builds on the List-Unsubscribe header format described in RFC 2369.

A typical header pair looks like this:

List-Unsubscribe: <https://email.example.com/unsubscribe/8f3b...>
List-Unsubscribe-Post: List-Unsubscribe=One-Click

The List-Unsubscribe URL should be recipient-specific and should accept an HTTPS POST request for the one-click flow. The List-Unsubscribe-Post field tells receiving software that the HTTPS endpoint supports the RFC 8058 mechanism.

Do not confuse this with an ordinary footer link. A footer link is clicked by a human and can lead to a preference page. The one-click header is consumed by participating mailbox software, which sends a request to the sender’s endpoint after the recipient uses the mailbox provider’s unsubscribe control. A mature marketing program should support both.

How an unsubscribe link works behind the scenes

The recipient sees a short piece of footer copy, but a dependable opt-out implementation involves identity, consent scope, data synchronization, and auditing.

1. The email contains a recipient-specific URL

A generic URL such as https://example.com/unsubscribe is rarely enough. It would force the recipient to identify themselves, sign in, or submit an email address, which adds friction and creates mistakes.

Instead, each outgoing message should contain a unique or securely resolvable unsubscribe URL, such as:

https://email.example.com/u/eyJzdWIiOiIxMjM0NTYifQ.signature

The token should be opaque to the recipient. Avoid putting a readable email address in a query string, such as ?email=person@example.com, because URLs can be copied, forwarded, logged, and stored in browser history. The token should be unguessable, signed, encrypted, or backed by a sufficiently random server-side record.

2. The destination identifies the subscription scope

Before changing a record, the system needs to know what the recipient is leaving. Common scopes include:

  • A single newsletter list.
  • A marketing topic, such as product news or events.
  • A geographic program.
  • All promotional email from a brand or sending entity.
  • A marketing stream within a multi-tenant platform.

Scope should be intentional. A person who opts out of a weekly newsletter may still want account security alerts, order confirmations, invoices, or legally required notices. At the same time, a sender should not use narrow list-level semantics to keep mailing someone who clearly selected an all-marketing opt-out.

3. The system writes a durable suppression record

An opt-out cannot live only in the campaign tool that received the click. It should flow to the systems that can send future marketing mail: the customer database, CRM, marketing automation platform, audience warehouse, event pipeline, and email provider integration.

The most durable design is a central suppression service or canonical consent record. Sending applications consult it before building recipient batches, while event processors update it immediately after an unsubscribe event. This avoids the classic failure where a person unsubscribes from one newsletter tool but continues receiving automated promotions triggered by another application.

4. Future sends check the suppression state

The sender must enforce opt-outs before enqueueing or transmitting marketing email. Suppression should not depend solely on a nightly batch job because campaigns and behavioral automations can send at any time.

A typical decision flow is:

  1. Determine the message classification: transactional, marketing, or mixed.
  2. Resolve the recipient’s global and category-level preferences.
  3. Exclude the recipient if the relevant marketing scope is suppressed.
  4. Send only if the message is permitted under the sender’s policy and applicable rules.
  5. Record the decision and message category for auditability.

This logic is particularly important for automation. A recipient may unsubscribe at 10:03 a.m. while an abandoned-cart, upsell, or reactivation event is already scheduled for 10:10 a.m. The system needs a final preference check close to send time.

5. The sender records an auditable event

Keep enough information to investigate disputes and diagnose system failures. A useful unsubscribe record can include the recipient identifier, timestamp, sending domain or brand, preference scope, campaign or message ID, acquisition source when available, and the event source such as footer link, mailbox-provider one-click request, support action, or API import.

Do not interpret auditability as a reason to keep excessive personal data forever. Store the minimum information needed for suppression, compliance, and operational troubleshooting, then apply the organization’s privacy and retention policies.

Where to place an unsubscribe link in an email

The footer is the normal location because recipients expect account, legal, address, and preference information there. But placement is not simply a design convention. The link must be noticeable enough that an ordinary recipient can locate and use it.

Make the link clear, readable, and functional

Use direct language. A footer that says Unsubscribe is usually clearer than a vague phrase such as Manage communication experience. A preference-center link can be useful, but it should not conceal the ability to opt out.

Good footer copy might read:

You are receiving this because you signed up for Acme product updates.
Manage preferences or unsubscribe from marketing emails.

The typography should remain readable on mobile devices. Avoid placing the link in an image, using an extremely small font, setting it in low-contrast gray text, or burying it after a wall of legal copy. It should work with images disabled and in dark-mode email clients.

Include it in HTML and plain-text content

Many senders provide multipart emails with both HTML and plain-text versions. The plain-text part should contain an unsubscribe URL too. A recipient who reads the text version should not lose the same opt-out capability available in the visual version.

For example:

To stop receiving Acme product updates, unsubscribe here:
https://email.example.com/u/recipient-token

The text can be different from the HTML presentation, but the underlying preference action should be equivalent.

Do not turn the unsubscribe page into a retention trap

A sender may offer options before the final confirmation, such as receiving fewer emails, switching to a monthly digest, or selecting only specific subjects. These options can be valuable when they are genuinely optional.

They become a problem when the page requires a survey, repeatedly asks the recipient to reconsider, obscures the full opt-out option, requires account login, or makes the recipient navigate several steps before their request is honored. The exit should be easier than the sales pitch.

Common unsubscribe link problems and their causes

An unsubscribe issue is not a bounce type. A bounce is a delivery failure reported by the receiving mail server; an unsubscribe is an intentional preference event. Still, both can reveal list-quality or system-design problems, and both should be monitored.

The link is missing from some message types

A common cause is template drift. A brand may have a compliant newsletter template but forget the footer in an older template, a regional template, a hand-coded announcement, a triggered campaign, or a newly launched product email.

Mixed-purpose messages create another gap. A password-reset email normally does not need a marketing unsubscribe link, while a product-recommendation email might be promotional even if it is part of an automated workflow. Classify messages based on their primary purpose, not just the software that sent them.

The link goes to the wrong recipient or list

This can happen when a reusable template references the wrong merge field, a token is cached across recipients, a test token accidentally reaches production, or a campaign platform and customer database disagree on identity.

The result is serious: one recipient may alter another person’s preferences, or a recipient may see a confusing error. Use recipient-specific test messages and inspect generated URLs before launches. Tokens should be bound to the intended recipient and, where appropriate, to the permitted preference scope.

The URL is broken or altered by tracking

Link tracking, URL rewriting, security scanners, and redirect services can all affect an unsubscribe URL. A tracking wrapper may mis-handle query parameters; a redirect may lose the token; a security product may prefetch a URL; or an old domain may expire after a rebrand.

Treat unsubscribe links as critical paths. Test them after enabling click tracking, changing domains, moving providers, updating templates, or altering authentication and routing infrastructure. If click tracking must wrap the link, verify the final destination and opt-out event—not merely that the browser lands on a page.

The request is recorded but not enforced everywhere

This is one of the most damaging operational failures. The preference center says the user is unsubscribed, but a separate marketing automation tool, CRM export, or product notification service continues sending promotions.

The root cause is usually fragmented data ownership. Fix it with a canonical suppression source, clear ownership, integration tests, and reconciliation jobs that compare recent unsubscribe events with the audiences used by every marketing sender.

The sender treats all email as one category

Overbroad suppression can stop important operational messages, while overly narrow suppression can keep marketing mail flowing after a recipient tries to leave. Both harm trust.

Define message categories in advance. For example, account security, receipts, and service notifications may have a different policy from newsletters, cross-sells, event invites, and promotional lifecycle campaigns. Document who decides when a message is mixed-purpose and how preferences apply.

A sudden rise in unsubscribes comes from audience or content mismatch

A higher unsubscribe rate often means more than one thing. It may follow a frequency increase, a broad acquisition campaign, a weakly disclosed signup form, an irrelevant promotion, a major brand change, seasonal interest changes, or sending to people who have not heard from the brand for a long time.

Break the data down before reacting. Compare unsubscribes by acquisition source, list age, geography, device, campaign, send time, subscriber tenure, content category, and frequency cohort. The right response may be better onboarding, tighter segmentation, lower frequency, a re-permission campaign, or stopping a poor-quality acquisition source—not simply redesigning the footer.

How to improve unsubscribe handling and reduce unwanted opt-outs

The goal is not to make unsubscribing harder. The goal is to send messages that the right people continue to value while making departure respectful and reliable for everyone else.

Set expectations at signup

The best unsubscribe strategy begins before the first message. Tell people what they are signing up for, which brand will email them, what kinds of messages they will receive, and approximately how often.

A signup form that quietly adds users to several unrelated lists may produce short-term list growth but weak long-term engagement. Clear expectations improve permission quality and make later campaign results easier to interpret.

Use preference centers for meaningful control

A well-designed preference center lets recipients choose options that match actual sending streams. Useful controls may include:

  • Product updates versus promotional offers.
  • Weekly, monthly, or occasional digests.
  • Event invitations by location.
  • Educational content versus sales announcements.
  • Temporary pauses, where appropriate.
  • A clear all-marketing unsubscribe option.

Do not offer preferences you cannot operationally honor. If a checkbox says Monthly emails only, the send orchestration must enforce that preference across every relevant campaign and automation.

Segment before increasing frequency

A single email cadence rarely suits every subscriber. New users, highly engaged customers, inactive leads, trial users, and long-time buyers can have different informational needs.

Before increasing campaign volume, identify who has recently engaged, who has explicitly asked for updates, and who is becoming dormant. Frequency caps and segment-level policies can prevent the fatigue that often drives unsubscribe spikes.

Re-engage or suppress inactive recipients

Sending indefinitely to unengaged contacts can create more than unsubscribe risk. It can increase complaints and eventually expose the sender to recycled or invalid addresses.

Build an inactivity policy that fits the program. For example, after a defined period without engagement, reduce frequency, send a targeted reconfirmation message, or stop promotional mail unless the person opts back in. Do not use opens alone as the only signal, because privacy features and image behavior can make open tracking unreliable. Combine clicks, site activity, purchases, explicit preferences, and recency where lawful and appropriate.

Test the entire flow, not only the template

A real unsubscribe test should verify the complete chain:

  1. Send a test message to a controlled inbox.
  2. Check the HTML footer and plain-text version.
  3. Confirm the visible link opens correctly on desktop and mobile.
  4. Confirm the recipient-specific token is valid and not exposed as readable personal data.
  5. Select the full opt-out option.
  6. Confirm a suppression event is recorded with the right scope.
  7. Attempt a new marketing send through every relevant channel.
  8. Confirm the recipient is excluded.
  9. Confirm legitimate transactional messages follow the documented policy.
  10. Test the List-Unsubscribe one-click endpoint separately with a safe test recipient.

Teams that send through SMTP or an API should include these tests in release and migration checklists. The email API reference and setup guides can help engineering teams keep message assembly, headers, and sending behavior consistent across applications.

Keep lists healthy before you send

An unsubscribe link handles an intentional request; it does not solve bad addresses, typo-filled forms, role accounts, or stale imported records. Sending to poor-quality addresses can produce bounces and complaint problems that damage deliverability even if the unsubscribe process is excellent.

Validate addresses at collection time, use confirmed permission where appropriate, and monitor acquisition sources. For a quick pre-send check, use an email address verification tool alongside your broader consent and list-hygiene process.

Technical guidance for one-click unsubscribe headers

Header-based unsubscribe support deserves its own implementation review because it is easy to appear correct while failing in production.

Publish both required header fields for one-click support

For an HTTPS-based RFC 8058 flow, include List-Unsubscribe with the recipient-specific URL and List-Unsubscribe-Post with the exact one-click indicator:

List-Unsubscribe: <https://email.example.com/unsubscribe/recipient-token>
List-Unsubscribe-Post: List-Unsubscribe=One-Click

The URL goes in angle brackets. Avoid placing ordinary HTML URLs, tracking redirects, or a login-gated preference page in this field. The receiving mailbox provider needs to be able to submit the request directly to the endpoint.

A sender can also publish a mailto: method in a List-Unsubscribe header, but an email-based method does not provide the same RFC 8058 HTTPS POST flow. If you need one-click unsubscribe support, implement the HTTPS endpoint and the List-Unsubscribe-Post field rather than assuming mailto: is sufficient.

Accept the POST without user interaction

The endpoint must process a valid request without a confirmation form, cookie requirement, CAPTCHA, login wall, or extra click. The mailbox provider, not the recipient’s browser, initiates this request.

This has design consequences. Do not rely exclusively on JavaScript, browser session state, or page-rendering logic. The backend route itself must identify the recipient securely from the URL token and apply the correct unsubscribe scope.

Protect against accidental or malicious requests

RFC 8058 exists partly because mail software can fetch URLs in message headers. The separate List-Unsubscribe-Post mechanism signals that the endpoint supports the intended one-click request rather than treating any fetch of a header URL as an unsubscribe action.

Use high-entropy tokens, TLS, rate monitoring, and careful request validation. Avoid predictable identifiers. If a token can be guessed, an attacker could attempt to alter recipient preferences. If the endpoint receives malformed or expired tokens, fail safely, log the event, and do not expose personal data in error messages.

Keep footer-link and header behavior aligned

The visible footer link may lead to a preference center, while the one-click header normally performs an immediate unsubscribe action. That is acceptable only if the scopes are clear and operationally aligned.

For example, if the header removes a person from all promotional messages but the footer says unsubscribe from weekly tips, recipients may receive inconsistent outcomes. Decide what each path means, document it, and communicate clearly in the email.

How to analyze unsubscribe rate without overreacting

Unsubscribe rate is useful as a directional metric, not a universal pass-or-fail benchmark. A healthy rate depends on list source, product category, lifecycle stage, send cadence, seasonality, and how aggressively the sender removes inactive contacts.

Compare like with like

Compare newsletters with prior newsletters, promotional campaigns with similar promotions, and onboarding emails with the same stage of onboarding. A weekly digest sent to people who explicitly requested it is not comparable to a broad announcement sent to a newly imported list.

Look at both the absolute number and the rate. Ten unsubscribes from 100 deliveries means something very different from ten unsubscribes from 100,000 deliveries. Also inspect the timing: a sudden first-hour spike can indicate that the audience did not expect the campaign, while a slow steady rate may reflect ordinary list turnover.

Pair unsubscribes with complaint and engagement signals

Useful companion metrics include:

  • Spam complaint rate.
  • Delivered volume.
  • Hard and soft bounce trends.
  • Click rate and conversion rate.
  • New subscriber source and signup date.
  • Repeat purchase or product-use activity.
  • Frequency per recipient over the previous 7, 30, and 90 days.
  • The share of recipients with no recent engagement.

An unsubscribe increase accompanied by fewer complaints may be less alarming than a low unsubscribe rate paired with rising complaints. In that case, people may be unable to find or trust the opt-out route and are choosing spam reporting instead.

Investigate changes with a practical checklist

When unsubscribe rate rises, ask:

  1. Did the email go to a different segment than usual?
  2. Was the audience acquired through a new form, partner, import, event, or promotion?
  3. Did message frequency increase recently?
  4. Was the subject line or content inconsistent with the signup promise?
  5. Did the campaign include a clear sender identity?
  6. Did a template, tracking domain, or preference-center change break the link?
  7. Are complaints also rising?
  8. Are unsubscribes concentrated among newer or older subscribers?
  9. Did the campaign send at an unusual time or after a long period of silence?
  10. Does the opt-out event reach every sending system quickly?

The answer should guide corrective action. If the problem is relevance, improve segmentation. If it is frequency, reduce cadence. If it is list acquisition, fix the form or source. If it is implementation, repair the pipeline before sending the next campaign.

Transactional email and unsubscribe links

Not every email needs the same opt-out behavior. Password resets, account-security alerts, receipts, invoices, and other operational notices can be necessary to provide a service the recipient requested. Suppressing those messages simply because someone left a marketing list can cause harm.

However, labels are not enough. A message called transactional can still contain a meaningful promotional purpose. An order confirmation that includes a small related-product recommendation may be primarily transactional, while a recurring product-recommendation email triggered by browsing behavior may be marketing. Assess the message’s primary purpose and maintain a policy that product, legal, and marketing teams understand.

A safe approach is to separate sending streams and templates. Keep marketing mail in a system that always checks marketing preferences, and keep critical service notifications in a distinct stream with tightly limited promotional content. This reduces accidental crossovers and makes both reporting and compliance review easier.

Unsubscribe link best-practices checklist

Before launching a campaign or automation, confirm the following:

  • The message is correctly classified as marketing, transactional, or mixed-purpose.
  • Marketing email includes a visible unsubscribe link in the HTML and plain-text versions.
  • The link text is clear, readable, and accessible on mobile.
  • The URL is recipient-specific and does not reveal the email address or other sensitive data.
  • The opt-out flow does not require login, a survey, CAPTCHA, or unnecessary steps.
  • The page offers a clear all-marketing opt-out even when category preferences are available.
  • The unsubscribe event writes to a canonical suppression record.
  • Every campaign and automation checks that record before sending.
  • List-Unsubscribe and List-Unsubscribe-Post are present where one-click unsubscribe is required or supported.
  • The HTTPS one-click endpoint accepts the expected POST flow and processes it without browser interaction.
  • Test recipients are excluded from the next marketing message after opting out.
  • Transactional-message behavior is documented separately from marketing suppression behavior.
  • Reporting tracks delivered email, unique unsubscribes, complaints, and list-source trends.

Conclusion

An unsubscribe link is a core part of responsible email sending, not a reluctant footer requirement. It gives recipients control, lowers the chance that unwanted messages become spam complaints, improves the quality of marketing audiences, and helps a sender meet important operational and compliance expectations.

The strongest programs do more than add a footer link. They use clear signup expectations, secure recipient-specific URLs, meaningful preferences, centralized suppression data, one-click header support for eligible marketing mail, and tests that prove an opt-out is enforced everywhere. Make leaving easy, and the people who remain are more likely to be the audience your campaigns were meant to reach.

FAQ

Is an unsubscribe link required in every email?

Marketing emails should include a clear, accessible unsubscribe link. Purely transactional messages, such as password resets or receipts, may follow a different policy because they are necessary service communications. Mixed-purpose messages should be reviewed carefully because promotional content can change the message’s classification.

What is a good unsubscribe rate?

There is no single good rate for every sender. Compare campaigns with similar audiences, purposes, and frequencies, then review unsubscribe rate alongside complaint rate, delivery performance, engagement, and list source. A low rate is not automatically positive if recipients cannot easily opt out.

Does an unsubscribe link hurt email deliverability?

No. A visible, functional unsubscribe link generally supports deliverability because it gives recipients an alternative to spam complaints. It can reduce list size, but it helps preserve a more engaged and permission-based audience.

What is the difference between an unsubscribe link and one-click unsubscribe?

An unsubscribe link is the visible link inside the email body, usually in the footer. One-click unsubscribe is a header-based mechanism that lets supported mailbox providers display their own unsubscribe control and submit an HTTPS POST request to the sender’s endpoint.

How fast should an unsubscribe request take effect?

Operationally, it should take effect as quickly as possible, ideally immediately across all marketing sending systems. In the United States, CAN-SPAM requires commercial email opt-out requests to be honored within 10 business days, but waiting that long is a poor recipient experience and increases the risk of unwanted follow-up messages.