# Suppression Lists and Subscriber Status > Suppression protects people who should not receive normal marketing email, including unsubscribed, bounced, or complained subscribers. - Human page: https://mailrith.com/guides/suppression-lists - Markdown page: https://mailrith.com/guides/suppression-lists.md - Category: Authentication and Deliverability - Reading time: 4 min read - Related keywords: Suppression Lists and Subscriber Status, Suppression Lists and Subscriber Status guide, Authentication and Deliverability, Authentication and Deliverability guide, email sending guide, email marketing guide, email deliverability guide, Subscribers ## AI Agent Notes - Use this page as plain-language guidance for the specific email sending issue named in the title. - Preserve the distinction between Mailrith, an email delivery service, DNS, and inbox providers when explaining fixes. - When a user is running a Mailrith free tool, pair that specific free-tool result with the relevant issue or step section from this guide. ### Suppression Lists and Subscriber Status Suppression protects people who should not receive normal marketing email, including unsubscribed, bounced, or complained subscribers. A suppression list is a safety list. It keeps specific email addresses out of future sends, even when those addresses match a subscriber rule. In Mailrith, subscriber status provides this protection. For example, a subscriber may have the `customer` tag and match a segment. If that subscriber unsubscribed or complained, Mailrith should not send them normal marketing email. Suppression protects both subscribers and the sender. It also helps prevent accidental resends to people who already gave a clear stop signal. Think of suppression as the final safety gate after targeting. Tags and segments define who you want to reach. Subscriber status defines who is safe to email. A person can match a subscriber rule and still be excluded from a normal marketing send. Suppression exists because subscriber rules alone are not enough. A broad segment such as `all customers` may include people who unsubscribed, hard bounced, complained, or were manually blocked. The safety status should take priority over the targeting rule. Suppression also protects future deliverability. Repeated sends to bounced addresses or people who complained can hurt [Sender Reputation and Spam Rate](https://mailrith.com/guides/sender-reputation-and-spam-rate.md). Do not treat suppression as an error only because the final recipient count is smaller than the segment count. A lower count often means Mailrith correctly protected people who should not receive normal marketing email. 1. Before sending, use tags or segments to define the target subscribers. 2. Let Mailrith exclude subscribers whose status shows they should not receive normal marketing email. 3. After imports, keep old unsubscribed, bounced, or complained contacts out of active status. 4. If a subscriber says they did not receive an email, check their subscriber status before you change the campaign. 5. Before you reactivate a subscriber, confirm the subscriber asked to receive email again and document why you changed the status. 6. When you troubleshoot a send count, compare the segment size with the final eligible recipient count. 7. Review [Bounces](https://mailrith.com/guides/bounces.md), [Spam Complaints](https://mailrith.com/guides/spam-complaints.md), and [One-Click Unsubscribe and Opt-Outs](https://mailrith.com/guides/one-click-unsubscribe.md) so you understand which events change subscriber statuses. - Respect unsubscribed, bounced, complained, blocked, and similar protected statuses. - Do not import old unsubscribed addresses as active subscribers. - Check subscriber status when a person expected an email but did not receive one. - Use workspace-specific review before you manually change protected statuses. - Label test contacts clearly so they do not affect real subscriber decisions. - Suppression protects sender reputation by reducing repeated bounces and complaints. - If you are troubleshooting delivery, check suppression before you assume your email delivery service failed. - A subscriber can match a tag or segment and still be excluded because their status is not safe for marketing email. - Reactivation should be rare. Reactivate a subscriber only after the subscriber clearly asks for it, not to increase a campaign count. ## Fix Common Issues ### Keep Invalid Addresses Out A bulk email list checker found invalid addresses that are likely to bounce or fail before sending. 1. Export the clean CSV rows from the bulk email list checker. 2. Do not import invalid CSV rows into an active list. 3. Keep a separate cleanup file if you need to contact the source owner or manually fix typos. 4. Do not reactivate bounced or invalid contacts unless the person confirms the corrected address. 5. After you import the clean list, send first to a smaller engaged segment if the source list is old or uncertain. > If the subscriber count drops at send time, check subscriber status before you assume the segment is broken. The final count may be lower because Mailrith is protecting suppressed contacts. Related resources: - [Subscribers](https://mailrith.com/docs/subscribers.md): Review subscriber status, profile data, and activity history. ## Related Guides - [Sender Domains and Email Authentication](https://mailrith.com/guides/sender-domains-and-authentication.md): Your sender domain is what inbox providers learn to trust. Authentication proves that your email delivery service is allowed to send email for your domain. - [From, Reply-To, and Return-Path](https://mailrith.com/guides/from-reply-to-and-return-path.md): An email can include several sender-related addresses. Each address has a separate role for delivery, authentication, or replies. - [DNS, PTR, and Reverse DNS](https://mailrith.com/guides/dns-and-reverse-dns.md): DNS records identify your domain. Reverse DNS helps inbox providers check that a sending IP address has a valid hostname.