mbox corruption

V

vingertop

Verified User
Joined
Jan 9, 2006
Messages
39
Location
The Netherlands
Hi All,

I got 2 users now wit a corrupt mbox file.
Webmail or popping mail will give this error in the system maillog /var/log/maillog :

Mar 29 22:57:12 in2ict01 vm-pop3d[77785]: Unable to use "username" mailbox; using /dev/null for testing
Mar 29 22:57:12 in2ict01 vm-pop3d[77785]: User "username" logged in
Mar 29 22:57:12 in2ict01 vm-pop3d[77785]: Session ended for user: "username"

It got me worried but mail is actually still delivered in the mbox file , i can see the date changing , the file growing , and when viewing the file i can see the messages. The file seems perfeclty ok.

Renaming the original mbox file and touching a new file gets the mailflow back up again and solves the problem. Execpt for the messages still in the corrupt file.

I disabled spamassassins for the domain , this does not help. I googled some , that learned me mbox files seem to be sensitive for corruption because of locking problems, i know , no FUD on these forums but this is the general feeling i get reading posts.

For this i decided to convert the mailflow to "Maildir" as many google hits suggest.

But till then i got users with corrupt mbox files , any tips on how to solve these corrupted mbox files ?
 
We've never had an mbox file corrupted because of a locking problem; that generally occurs when using a remote file system such as NFS, which doesn't support locking well.

But have had mbox file corruption because some spams have non-compliant headers that break the mbox delivery. Why spammers would do that I can't be sure, but we've seen it.

Jeff
 
Well .... the following occured: i got a message from the user thanking me for fixing the email problem so fast....

I DID ABSOLUTLY NOTHING TO FIX THIS :D

Mail just started to flow again!?

Anyhow , i`m preparing for the upgrade towards the dovecot maildir based system. This seems to be the way to go.

Just for my curiosity, since you have also seen this problem, what were the actions you took for solving the corrupted files ?
 
vingertop said:
Well .... the following occured: i got a message from the user thanking me for fixing the email problem so fast....

I DID ABSOLUTLY NOTHING TO FIX THIS :D

Mail just started to flow again!?
Click to expand...
Possibly he was getting a timeout error and his local mail program wasn't properly reporting it. The mailserver will attempt to deliver multiple emails at the same time if the local program requests it. This can cause a lot of jumping around in an mbox file, which can cause a timeout.

Perhaps he was getting one or more additional emails downloaded each time he tried, or else the server was finally less busy, and finally he could download the email he couldn't download prevoiusly. So the problem I saw may have been completely different.
Anyhow , i`m preparing for the upgrade towards the dovecot maildir based system. This seems to be the way to go.
Click to expand...
Definitely.
Just for my curiosity, since you have also seen this problem, what were the actions you took for solving the corrupted files ?
Click to expand...
We delete the top email in the mbox file; it's usually spam anyway :) .

Jeff
 
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