[CentOS] Fail2ban mail failures ???

Sat Dec 27 14:22:04 UTC 2014
James B. Byrne <byrnejb at harte-lyne.ca>

On Fri, December 26, 2014 12:59, Mike Burger wrote:
> On 2014-12-26 12:39 pm, Robert G. (Doc) Savage wrote:
>> I'm using fail2ban with CentOS 6.6. Something is causing fail2ban's
>> alerts sent to root's mail to be rejected. Here's a clip from one of
>> the
>> error messages:
>>
>>
>>         Message 48:
>>         From MAILER-DAEMON at lion.protogeek.org  Sun Dec 21 03:09:20 2014
>>         Return-Path: <MAILER-DAEMON at lion.protogeek.org>
>>         Date: Sun, 21 Dec 2014 03:09:19 -0600
>>         From: Mail Delivery Subsystem
>> <MAILER-DAEMON at lion.protogeek.org>
>>         To: postmaster at lion.protogeek.org
>>         Content-Type: multipart/report; report-type=delivery-status;
>>         	boundary="sBL97EKS003880.1419152959/lion.protogeek.org"
>>         Subject: Postmaster notify: see transcript for details
>>         Auto-Submitted: auto-generated (postmaster-notification)
>>         Status: R
>>
>>         Part 1:
>>
>>         The original message was received at Tue, 16 Dec 2014 03:09:17
>>         -0600
>>         from localhost
>>         with id sBG97E83025627
>>
>>            ----- The following addresses had permanent fatal errors
>>         -----
>>         <fail2ban at example.com>
>>
>>            ----- Transcript of session follows -----
>>         <fail2ban at example.com>... Deferred: Connection timed out with
>>         example.com.
>>         Message could not be delivered for 5 days
>>         Message will be deleted from queue
>>         ..........
>>
>>
>>
>> I used to get the messages that are now being deleted after five days.
>> Any suggestions?
>
> I would suggest looking at the mailer daemon logs on both the sending
> and receiving systems. It would appear that the sending system is having
> difficulties at the receiving system end.
>
> You will likely find the root of your issues in the log entries for that
> message (or those messages) that occurred over the 5 days in question.
>

Just checking the obvious but can you confirm that you are not actually
sending messages to example.com?

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