# Bounces > A bounce means an email could not be delivered, and repeated mailing to bad addresses can hurt future delivery. - Human page: https://mailrith.com/guides/bounces - Markdown page: https://mailrith.com/guides/bounces.md - Category: Authentication and Deliverability - Reading time: 5 min read - Related keywords: Bounces, Bounces guide, Authentication and Deliverability, Authentication and Deliverability guide, email sending guide, email marketing guide, email deliverability guide, Email Delivery Connections, Sender Reputation and Spam Rate ## 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 free tool, pair the tool result with the relevant issue or step section from this guide. ### Bounces A bounce means an email could not be delivered, and repeated mailing to bad addresses can hurt future delivery. A bounce happens when an email cannot be delivered. Some bounces are temporary, such as a full mailbox or a temporary email delivery service issue. Others are more permanent, such as an address that does not exist. Hard bounces usually mean the address should not receive normal future sends. Examples include an address that does not exist or a domain that cannot receive mail. Continuing to mail bad addresses tells inbox providers that the list is not well maintained. Soft bounces can happen for temporary reasons. A mailbox may be full, a receiving server may be temporarily unavailable, or your email delivery service may throttle traffic. That service may retry soft bounces before giving up. Email delivery service event names can differ, but the idea is the same: some failures are temporary, some are final. When you read results, do not lump every bounce together without checking the reason. Email delivery service webhooks are important because they let Mailrith receive bounce events and update subscriber status. Without webhooks, the service may know about a bounce but Mailrith may not receive the event. High bounces often point to a subscriber-list problem. Old imports, purchased lists, typo-heavy forms, unverified signups, and stale addresses can all create bounces. Fixing bounces usually means improving list collection and cleanup, not rewriting the email body. 1. Set up email delivery service webhooks from [Email Delivery Connections](https://mailrith.com/docs/email-delivery-connections.md). 2. After a send, review bounces in Mailrith and in your email delivery service dashboard if needed. 3. Separate hard bounces from temporary or soft bounces when your email delivery service gives that detail. 4. If many addresses bounce, pause sending to that list and inspect the source. 5. Do not manually reactivate hard-bounced addresses unless the address owner confirms the address is valid. 6. Before importing an old list, clean obvious invalid addresses and send to a small test segment first. 7. Use [Suppression Lists and Subscriber Status](https://mailrith.com/guides/suppression-lists.md) so bounced addresses stay out of future normal sends. - Watch bounce rate after imports, launches, and old-list campaigns. - Remove or suppress addresses that hard bounce. - Check email delivery service webhooks if bounce events appear in the email delivery service dashboard but not in Mailrith. - Do not retry a large failed send without understanding why it bounced. - Use smaller tests when list quality is uncertain. - High bounces can damage [Sender Reputation and Spam Rate](https://mailrith.com/guides/sender-reputation-and-spam-rate.md). - Bounced subscribers should usually be protected by [Suppression Lists and Subscriber Status](https://mailrith.com/guides/suppression-lists.md). - If bounces appear in your email delivery service but not in Mailrith, check webhook setup before trusting Mailrith's event count alone. - If one domain bounces heavily, such as one company or mailbox provider, inspect the error reason before suppressing the whole list. ## Fix Common Issues ### Mail Records Do Not Prove a Mailbox Exists An email checker found MX records for the domain, but that only proves the domain can receive mail somewhere. It does not prove the exact inbox exists. 1. Keep the address only if the subscriber gave it through a trusted source. 2. Use normal subscriber activity, confirmation, or a successful send to build confidence. 3. Watch for bounces after the first send. 4. Do not use SMTP probing as proof of permission. ### Domain Without MX Records A checker found no MX records for the email domain, though the domain may still have address records. 1. Ask the subscriber to confirm the address before importing it. 2. Check whether the domain is spelled correctly. 3. If it is your own domain, add proper MX records through the mailbox provider. 4. Avoid sending at volume to addresses on domains without normal receiving records. ### Domain Cannot Receive Mail A checker found no MX, A, or AAAA records for the email domain, so the domain does not currently look reachable for email. 1. Do not import or send to the address as an active subscriber. 2. Check whether the domain was mistyped. 3. Ask the subscriber for a corrected address. 4. If the domain belongs to you, fix DNS before trying to send mail to addresses on it. > A hard bounce is a stop sign. Do not keep sending normal marketing email to an address that your email delivery service says does not exist. Related resources: - [Email Delivery Connections](https://mailrith.com/docs/email-delivery-connections.md): Set up email delivery service webhooks so bounce events reach Mailrith. - [Sender Reputation and Spam Rate](https://mailrith.com/guides/sender-reputation-and-spam-rate.md): Understand how high bounce rates can hurt future delivery. ## Related Guides - [Sender Domains and Email Authentication](https://mailrith.com/guides/sender-domains-and-authentication.md): Your sender domain is the name inboxes learn to trust, and authentication proves that your email delivery service is allowed to send for it. - [From, Reply-To, and Return-Path](https://mailrith.com/guides/from-reply-to-and-return-path.md): An email has several sender-related addresses, and each one has a different job in delivery and replies. - [DNS, PTR, and Reverse DNS](https://mailrith.com/guides/dns-and-reverse-dns.md): DNS records identify your domain, while reverse DNS helps inboxes check whether a sending IP has a sensible hostname.