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RPGoldenberg's profile

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Monday, November 20th, 2023 12:57 AM

e-mails sent to gmail accounts are bouncing back as undeliverable- need help with DKIM and SPF

why are my e-mails sent to gmail accounts bouncing back as undeliverable? Help with DKIM and SPM Recently my e-mails sent to anyone with a gmail account are undeliverable. The message I get is that I need to authenticate with DKIM and/or SPF. I don't know how to do this and ATT support said they did not have access to the servers to do this. Any suggestions? Below is the message: Sorry, we were unable to deliver your message to the following address. <[email scrubbed]>: 550: 5.7.26 This mail has been blocked because the sender is unauthenticated. 5.7.26 Gmail requires all senders to authenticate with either SPF or DKIM. 5.7.26 5.7.26 Authentication results: 5.7.26 DKIM = did not pass 5.7.26 SPF [] with ip: [] = did not pass 5.7.26 5.7.26 To mitigate this issue, please visit Gmail's authentication guide 5.7.26 for instructions on setting up authentication: 5.7.26 v16-20020a05622a131000b00417d78906c7si9910541qtk.292 - gsmtp Questions • Updated 3 days ago • Edited

Accepted Solution

Official Solution

Community Support


229.5K Messages

3 months ago

Hello @RPGoldenberg, thanks for reaching out to us AT&T Community and Forums. We understand the gravity of your concern. Lets provide you the help you need.

The error message you received indicates that the emails are being blocked because they are unauthenticated. This means that the receiving email server (in this case, Gmail) cannot verify that the emails are coming from you. To resolve this issue, you need to authenticate your emails using either SPF or DKIM.

SPF (Sender Policy Framework) is a method of email authentication that allows the receiving email server to verify that the email is coming from an authorized server. To set up SPF, you need to add a DNS record to your domain’s DNS settings. The record should specify which servers are authorized to send email on behalf of your domain.


DKIM (DomainKeys Identified Mail) is another method of email authentication that uses digital signatures to verify that the email is coming from an authorized sender. To set up DKIM, you need to generate a public-private key pair and add the public key to your domain’s DNS settings. The private key is used to sign outgoing emails, and the public key is used to verify the signature.


To get started with SPF and DKIM, we recommend visiting Gmail’s authentication guide. This guide provides detailed instructions on how to set up both SPF and DKIM for your domain.


We recomend that you reach out to the Gmail Support team for further invasion on your concern.


Let us know if this helps!


Fiona Q - AT&T Community Specialist!


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