AT&T Postmaster - Email Service Troubleshooting & Support

AT&T Postmaster Website

Resolve Your Email Issues

This site is intended for ISPs, E-mail providers and other service providers who want information about AT&T's e-mail service, how it works, and how to resolve related issues.


Spam

Spam is junk mail that comes to your email inbox.


Find out how you can avoid spam and report spam to AT&T.


Unblocking Messages

It is never the intention of the AT&T Postmaster staff to block legitimate mail. Unfortunately, legitimate messages are sometimes blocked as a result of our antispam and antivirus measures. We would like to rectify these problems as soon as possible, but we need your help.


Go to the Block Enquiry Website

Tips for Email Senders

This section contains AT&T's Best Practices for Email Senders:


Go to Email Best Practices


Not a Postmaster?

AT&T Internet Services customers having problems with your AT&T e-mail service


Go to AT&T Support Site

FAQ

It is never the intention of the AT&T Postmaster staff to block legitimate mail. Unfortunately, legitimate messages are sometimes blocked as a result of our antispam and antivirus measures. We would like to rectify these problems as soon as possible, but we need your help.

We have set up a website to streamline the process of requesting block-removals: http://www.att.net/blocks

Please visit this site for more information on the nondelivery-reports you might have received if you are a sender. You will also find there a form to submit requests for unblocking. This form is intended to be filled out by the administrator of sending systems that are blocked.

In most cases, requests sent through the website form will be granted and go into effect within two business days. We reserve the right to deny a request if our research shows that the sending system is in fact sending spam or otherwise abusing our network resources.

AT&T guidelines and standards for e-mail can be found in our Acceptable Use Policy. AT&T requires that all e-mail comply with the U.S Can Spam Act. Failure to adhere to the AT&T E-mail standards will results in your message being blocked from entering the AT&T network.

The maximum size of an email message that a AT&T customer can receive is based on the individual customer's service type.

Note: Message size includes the combined total of the message text and any message headers and attachments. (An attachment might double in size when it is coded for email.) The available space in the customer's mailbox may also determine if the message is received, regardless of the maximum message size.

Releasing personal and confidential information is against AT&T's Privacy Policy, for more information you can review detailed information on our Privacy Policy.

There are various factors that may cause an e-mail not to be delivered. First, try to send the message to your own e-mail account. If this is unsuccessful, please consider the following:

  • Confirm the e-mail address with your recipient. Check for correct spelling, and if there appears to be a space in the address, make sure that this "space" should not in fact be an underscore (_). Example: john_doe@bellsouth.net may appear as john_doe@bellsouth.net causing the underscore to look like a space.
  • Try to resend the message. Temporary problems between mail servers can sometimes affect mail delivery.
  • Your e-mail may be identified as SPAM and will be blocked from delivery if the recipient has their MailGuard set to "On". If this is the case, ask the recipient to change their MailGuard settings to "Review" and try resending the message. If the AT&T customer already has the MailGuard set to "Review", ask the recipient to forward your e-mail to thisisgood @ att.net (without the spaces). This will ensure that your message gets delivered and not be identified as SPAM.
  • If these suggestions do not resolve the problem, please contact your ISP for assistance. There may be a problem with the configuration of your mail client, or your ISP may be experiencing problems with their mail servers.

By adhering to AT&T's Acceptable Use Policy, your e-mail will most likely be delivered successfully to the customer's Inbox. If your e-mail meets the guidelines found in our Acceptable Use Policy but is still being filtered as SPAM, ask the AT&T customer to make sure their MailGuard is set to "Review" to allow SPAM messages to be delivered to a separate MailGuard folder for review. If MailGuard is set to Review and the problem persists, ask the recipient to forward the undeliverable e-mail message to thisisgood @ att.net (without the spaces). This will ensure that your message gets delivered and not be identified as SPAM.

There are several reasons why an e-mail may not to be delivered. In each case, the sender will receive an error message that provides more information about why the message was not delivered. Please refer to our E-mail Error List to determine the cause of the error you are receiving.

Information on the digital (DKIM) signatures added to outbound emails sent by AT&T customers is located on the DKIM Servers page of the AT&T Postmaster Web Site.

Most of our customers' accounts are hosted on the Yahoo! system.

A complete list of IP addresses for the AT&T Outbound Mail Servers can be found in the IP List for Outbound Mail Servers located on this site.