Why am I seeing increased email bounces at AT&T?
Summary
What email marketers say12Marketer opinions
Email marketer from Reddit shares that a sudden increase in bounce rates can often be attributed to changes in the recipient's email server policies or increased spam filtering. They suggest checking for any recent changes at AT&T.
Email marketer from Email Geeks shares that the bounce code they are seeing is "5.7.9 Message not accepted for policy reasons".
Email marketer from emailmarketingforum.com says it could be a temporary network issue at AT&T causing the bounces. Wait and see if this resolves.
Email marketer from Email Geeks explains they were seeing blocks like: 553 5.3.0 flpd575 DNSBL:RBL 521< xx.xx.xx.xx >_is_blocked.For assistance forward this error to <mailto:abuse_rbl@abuse-att.net|abuse_rbl@abuse-att.net>.
Email marketer from GlockApps suggests using a deliverability testing tool to check your email's placement at AT&T and other providers. This can help identify deliverability issues and misconfigurations.
Email marketer from Litmus says your bounces may be due to sending to old and invalid email addresses. You should ensure that email addresses are valid before you send to them.
Email marketer from AT&T Postmaster explains that if your mail server IP address is on a blocklist, AT&T will reject your emails. They recommend checking your IP address against common blocklists using online tools.
Email marketer from Mailjet answers that a likely cause is sending to too many bad email addresses. You should clean up your list to remove inactive or invalid addresses.
Email marketer from StackOverflow shares that problems with authentication (SPF, DKIM, DMARC) can cause higher bounce rates. Ensures records are set up correctly.
Email marketer from EmailonAcid explains that a sudden increase in bounces could be related to a drop in your IP reputation. Factors like sending spam, being added to blocklists, or sudden increases in email volume can negatively affect your reputation.
Email marketer from Email Geeks shares that they saw a noticeable increase in bounces at AT&T yesterday afternoon and submitted the issue to <mailto:abuse_rbl@abuse-att.net|abuse_rbl@abuse-att.net> but only received an auto-reply.
Email marketer from Sendgrid answers that AT&T might have implemented stricter filtering rules. Watch for any changes or announcements.
What the experts say5Expert opinions
Expert from Email Geeks shares a message that AT&T is aware of the bounce issues, and it's a problem on their side that they’re working on.
Expert from Spam Resource explains that AT&T is known to have somewhat aggressive spam filters and blocking policies, so increased bounces could be related to stricter filtering on their end.
Expert from Email Geeks confirms that AT&T has clearly increased blocking recently.
Expert from Email Geeks advises that the issue should be fixed, and if it’s not, open a ticket as Marcel suggested.
Expert from Word to the Wise explains that if your IP has been blocklisted by AT&T, you should follow their specific procedures for requesting delisting, which may involve submitting a form or contacting their abuse team.
What the documentation says4Technical articles
Documentation from RFC explains that 5xx SMTP error codes mean a permanent error. The email was not delivered and retrying will likely not help.
Documentation from Cisco explains that a 5xx error (like 5.7.1 or 5.7.9) indicates a permanent failure, meaning the email was not delivered. This can be due to various reasons including policy restrictions, spam filtering, or recipient mailbox issues.
Documentation from DKIM highlights that invalid or missing DKIM signatures can cause receiving servers to reject emails. Ensure emails are signed correctly.
Documentation from Microsoft explains that issues with your SPF (Sender Policy Framework) record can cause emails to be rejected by receiving servers. Make sure your SPF record is correctly configured to authorize your sending IP addresses.