POSTFIX bounces attachments over 10MB

[joelrob]

I'm using POSTFIX as a SMTP fronted relay to an Exchange 2007 backend. The default size for attachments in POSTFIX is 10 MB. I've set that in the configuration file to be 20 MB. When I look at postconf -n it verifies that the limit is set to 20 MB, (message_size_limit = 20480000). I've stopped and restarted the postfix service, but messages are still bounced back to my Exchange server as undeliverable if they exceed 10 MB in size. I)The bounce-back message users receive lists the Debian Linux / Postfix server as the server bouncing it back for exceeding size. Is there somewhere else this needs to be set?

Thanks.

 

[Noway2]

Are you perchance using another content scanner, such as Amavis or Spamassassin that could also be imposing limits?

As a side note, I too once wanted to set the receive limit higher on my Postfix mail system and ran into the same problem. I didn't spend any time on it, so I can't offer a solution.

 

[Noway2]

Edit - follow up: see this thread

http://www.cyberciti.biz/tips/postfix-mail-server-limit-the-mailbox-size.html

There appears to be both a message size and mailbox size limit that need to be adjusted.

 

[joelrob]

Noway2, thanks for responding. No other software running on the server yet, eventually it will have Kaspersky's gateway spam filter on it, but need to get POSTFIX running correctly first.

 

[joelrob]

To second post, the mailbox_size_limit is currently set to 0, meaning unlimited size. There shouldn't be any mailboxes on the server though as it's just being used to forward SMTP to and from the backend Exchange, but maybe it's holding it in a temp mailbox as it does so? My understanding from reading is that the limit = 0 works for attachment size in some versions of POSTFIX but hasn't in others, so I haven't tried that yet, but it may be my next step in troubleshooting the issue.