Visitor
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10 Messages
SMTP Auth failures and temporary fix
Assistance please. Port 587 stopped accepting connections and began giving a "452 4.1.0 TLS and Authentication required,..." message.
Last successfully used Dec 8
Log extract: Dec 8 15:31:24 mysys exim[28824]: 1mv3az-0007Ur-C5 => [Edited: "Personal Information"]oo.com R=cmcsa_p587 T=remote_auth587_cmcsa
S=4629 H=smtp.g.comcast.net [68.87.20.6]:25 I=[192.168.xx.xx]56192 X=TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256 CV=yes
DN="C=US,postalCode=19103,ST=Pennsylvania,L=Philadelphia,street=1 Comcast Center,O=Comcast Corporation,OU=Business Center,CN=smtp.comcast.net" C="250 2.0.0 v3b1moolaSLHyv3b2mQ4YA mail accepted for delivery" QT=3.458s DT=1.050s
Failure this morning Dec 17
Log extract: Dec 17 11:49:16 mysys exim[30552]: 1myDVO-0005ov-SX == [Edited: "Personal Information"]oo.com R=cmcsa_p587 T=remote_auth587_cmcsa
defer (-45) H=smtp-p.gslb4.comcast.com [96.102.167.162]:25: SMTP error from remote mail server after MAIL FROM:< [Edited: "Personal Information"]>
SIZE=5783: 452 4.1.0 TLS and Authentication required, for details see: https://www.xfinity.com/support/articles/email-client-programs-with-xfinity-email
There have been no changes to my local configuration, but I note that your comcast SMTP servers have changed recently...
After an afternoon of debugging and analysis, I discovered that if I changed my authentication credentials from
using 'smtp.comcast.net:USERID:PASSWORD', as is normal, and used the SMTP servers unique DNS name,
'smtp-p.gslb4.comcast.com:USERID:PASSWORD' it would authenticate and process the SMTP session correctly.
This successful transaction log:
Log extract: Dec 17 22:46:13 mysys exim[19397]: 1myQfi-00052o-Ob => [Edited: "Personal Information"] R=cmcsa_p587 T=remote_auth587_cmcsa
S=358 H=smtp-p.gslb4.comcast.com [96.102.18.195]:587 I=[192.168.xx.xx]49964 X=TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256 CV=yes
DN="C=US,postalCode=19103,ST=Pennsylvania,L=Philadelphia,street=1 Comcast Center,O=Comcast Corporation,OU=Business Center,CN=smtp.comcast.net" C="250 2.0.0 yQfjmAx12hkdByQfkmOKo3 mail accepted for delivery" QT=2.804s DT=2.238s
Although this fix works, I do not consider it a solution. Having the authentication credentials tied to
a specific Comcast SMTP server is not viable. when the SMTP server name rotates out, I fully expect authentication
failures again.
Regards.
user_be6da6
Contributor
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14 Messages
3 years ago
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bdf05061
New Poster
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5 Messages
3 years ago
Ran into the same annoying issue a week or two back. *.comcast.com is the annoying fix. Someone at comcast probably has no clue they made this error and wrecking havoc on auth for people that rely on smtp servers with *.comcast.net
https://forums.xfinity.com/conversations/email/authentication-required-error-on-exim-email-relay/61bc0edde41a4a46af423260?commentId=61bc1539f069681686038fbd
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user_44a3ca
Visitor
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1 Message
3 years ago
read this post, it solved the issue for me, no need to change any setting sin your email sending program either:
https://forums.businesshelp.comcast.com/conversations/connectivity/solved-smtp-server-port-auth-used-to-work-no-longer-does/615e0154dc872674e0fc3bd0?commentId=615e076fdc872674e0fc3ddb
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user_c5015a
Visitor
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3 Messages
3 years ago
read this post, it solved the issue for me, no need to change any settings in your email sending program either:
https://forums.businesshelp.comcast.com/conversations/connectivity/solved-smtp-server-port-auth-used-to-work-no-longer-does/615e0154dc872674e0fc3bd0?commentId=615e076fdc872674e0fc3ddb
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user_c5015a
Visitor
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3 Messages
3 years ago
this is the part of the post I added above that matters....log into the xfinity website with the email account you are trying to send from and go to your email on the site click the gear icon at top right, select Security in the left column, and enable access through third party programs.
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BruceW
Gold Problem Solver
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26.3K Messages
3 years ago
For reference: https://www.xfinity.com/support/articles/third-party-email-access
(edited)
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user_7e9bef
Visitor
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1 Message
3 years ago
So, can somebody please clarify the current status? I'm simply using SMTP from couple of webcams, which worked great until a few days ago.
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