[CentOS] Fail2ban mail failures ???

[Mike Burger]

On 2014-12-26 12:59 pm, 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.

PS: "Connection timed out with example.com" is the first thing I'd look 
at.
-- 
Mike Burger
http://www.bubbanfriends.org

"It's always suicide-mission this, save-the-planet that. No one ever 
just stops by to say 'hi' anymore." --Colonel Jack O'Neill, SG1