Why are there connection timeouts to AT&T domains?
Summary
What email marketers say7Marketer opinions
Email marketer from Mailhardener HardenMail suggests that AT&T is seeing you send a lot of emails and is doing a grey-listing check (temporary block) so that it can determine if you are legitimate. HardenMail suggests that you should ensure you are properly authenticated (SPF/DKIM/DMARC setup correctly) so you don't get grey listed.
Email marketer from EmailDeveloperForums user MailGuy shares that AT&T's mail servers might be throttling connections from specific IP ranges to prevent abuse, causing timeouts. Implementing proper SPF, DKIM, and DMARC records can help improve deliverability and reduce the likelihood of being throttled.
Email marketer from Reddit user u/SomeTechGuy explains that AT&T sometimes has issues with their mail servers, leading to temporary connection timeouts, and suggests checking AT&T's service status page or contacting their support for updates.
Email marketer from DNSQueries NetworkAdmin suggests that AT&T's mail servers might be undergoing maintenance, which can cause intermittent connection problems and timeouts. Checking AT&T’s official communication channels for any scheduled maintenance announcements is recommended.
Email marketer from StackOverflow TechGuru states that one common reason for connection timeouts to specific domains, including AT&T, is that their mail servers might be temporarily blacklisted due to spam complaints or unusual traffic patterns. It could resolve itself, but checking blacklist status is wise.
Email marketer from EmailGeeks user EmailPro responds that AT&T’s mail servers may temporarily reject connections if they detect unusual or suspicious email patterns, resulting in timeouts. Monitoring email sending behavior and addressing any potential issues flagged by AT&T can help prevent future timeouts.
Email marketer from EmailSecurityFAQ explains that aggressive firewall settings on AT&T's side might be blocking connections from certain IPs or networks, leading to timeouts. Checking if your IP is blocked and contacting AT&T to whitelist it might resolve the problem.
What the experts say4Expert opinions
Expert from Word to the Wise shares that one reason for timeouts to AT&T can be if they are detecting spam complaints or unusual sending patterns from your IP address. They recommend checking your sender reputation and resolving any blacklisting issues to reduce timeouts.
Expert from Email Geeks shares that she can’t seem to connect to those hosts manually and even pinging the machine results in 100% packet loss.
Expert from Spam Resource responds that AT&T sometimes has temporary issues with their email servers, particularly after updates or during periods of high traffic. This may cause connection timeouts. Monitoring their network status and retrying connections later may resolve the issue.
Expert from Email Geeks says he can connect, but it’s taking upwards of 20 seconds to get a banner back and guesses they’re overwhelmed or under a ddos.
What the documentation says4Technical articles
Documentation from AT&T Support explains that high traffic volume on their mail servers can lead to connection timeouts, especially during peak hours. They suggest retrying at off-peak times or upgrading to a business-class service with higher bandwidth allocation.
Documentation from MXToolbox indicates that connection timeouts to AT&T domains might result from misconfigured DNS settings or incorrect MX records. They recommend verifying the DNS configuration and MX records using their diagnostic tools to identify and resolve any issues.
Documentation from Postmaster.ATT.com states that AT&T uses rate limiting to protect their email infrastructure. Senders exceeding defined thresholds may experience connection timeouts. Reviewing their sending policies and adjusting sending volumes accordingly is essential to avoid timeouts.
Documentation from RFC Editor mentions that transient network issues, such as routing problems or temporary outages, can cause connection timeouts when attempting to connect to any mail server, including AT&T. These issues are often temporary and resolve themselves without requiring specific action.