AT&T is one of the largest telecommunication providers in the United States. The modern AT&T company was created in 1983 as the result of the breakup of the original AT&T telephone monopoly. The breakup of AT&T created numerous regional telephone providers including Bellsouth and Southwestern Bell (SBC).
SBC acquired AT&T in 2005, assuming the AT&T company name, and subsequently acquired Bellsouth in 2006.
Infrastructure
AT&T, Bellsouth, and SBC use the Yahoo email infrastructure to filter messages. The receiving Mail Transfer Agent (MTA) is located within AT&T's network. Messages accepted at the gateway by AT&T servers are relayed to the Yahoo anti-spam filters, and displayed within the AT&T/Yahoo webmail platform.
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Region |
North America; U.S. |
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Domains |
Ameritech.net; att.net; bellsouth.net; flash.net; nvbell.net; pacbell.net; prodigy.net; sbcglobal.net; snet.net; swbell.net; wans.net; worldnet.att.net |
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Connection/throughput |
Suggested MTA settings:
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Feedback loop (FBL) application |
Feedback Loop through Yahoo |
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Postmaster site |
Validity partnership with AT&T, Bellsouth and SBC
AT&T, Bellsouth and SBC use the Validity Certified allowlist through shared use of the Yahoo Infrastructure. Allowlisting includes sbcglobal.net, bellsouth.net, and att.net.
AT&T, Bellsouth and SBC delivery mediation
AT&T has a public escalation process by sending an email to abuse_rbl@abuse-att.net, which allows senders to email an unblock request to the block list group. AT&T also has information about the error codes they return available on their Postmaster website.
Validity guidance
Validity understands the Yahoo infrastructure well and may have data to diagnose deliverability issues. Refer to both AT&T and Yahoo deliverability best practices and postmaster page for additional details on improving deliverability.
