Inbox fles and possible bug

[Miguel Koren OBrien de Lacy]

Gentlemen;

On one server I have Fedora Core 4 running with all the yum updates, Mail Scanner 
4.50.10-3 and Clam 0.88.4. This server has about 100 email accounts. Last month and 
again today the same person complained about not being able to download emails using 
Outlook configured to access pop accounts, but only on one of his accounts (the same 
one both times). I checked a telnet to port 110 and found that dovecot reports that 
the file can not be accessed. This file in /var/spool/mail was there so I checked to 
permissions and size and all was well. I opened it up and noticed that it had a 
blank line at the top of the file. So on a hunch I made a copy and removed the blank 
line. After that everything worked again. This was the only mailbox file with a 
blank line at the top out of a random sampling of mailbox files I looked at. This is 
the first malbox "corruption" I have seen since I started using Linux in 1997, so 
having 2 cases with the same account in a short period seems like something more 
than coincidence.

My conclusion is that dovecot is particularly intolerant of the file format but also 
that something is putting in the blank line. The blank line does not have space 
charaters, just a line break. My prime suspect at the moment for doing this is 
MailScanner because it works on the emails before final delivery. I think that this 
user gets some type of email content that causes Mail Scanner to insert the spurious 
character at the start of the header and that if this happens with the first email 
received after the mailbox is emptied, the problem happens.

So the questions are if anybody has seens a similar problem and if my theory about a 
subtle "bug" in MailScanner make sense?

Miguel

--
Konsultex Informatica (http://www.konsultex.com.br)


-- 
Esta mensagem foi verificada pelo sistema de antivírus e
 acredita-se estar livre de perigo.