Mark, The bounce back error comes from the Exchange server. It lists the POSTFIX server as the server that is rejecting the attachment based on size. The Exchange connector to the POSTFIX server is set to accept attachments up to 20 MB and on the back end I can send attachments up to 20 MB from user to user. Also, it was working fine when it was a Windows front-end server with TrendMicro’s IMSS running on it. It’s only since the switch to Debian Linux/POSTFIX that messages over 10 MB are being rejected.
I can test with telnet and post the results asap. Nothing shows in the POSTFIX log if I’m tailing it while testing it. The Exchange logs just say that it’s been rejected by the POSTFIX server. Thanks for your suggestions. Joel Roberts Network Administrator From: Mark Homoky [mailto:mark.hom...@lingidiom.com] Sent: Thursday, October 13, 2011 4:28 PM To: Joel Roberts Cc: postfix-users@postfix.org Subject: Re: Attachment Limit Size On 13 Oct 2011, at 23:08, Joel Roberts <joel.robe...@pinkardcc.com<mailto:joel.robe...@pinkardcc.com>> wrote: Hi all, new to the group. Have recently setup POSTFIX as an SMTP relay front end to an Exchange 2007 backend. Have encountered the following issue: I'm using POSTFIX as an SMTP fronted relay to an Exchange<http://www.tek-tips.com/viewthread.cfm?qid=1663396&page=1> 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<http://www.tek-tips.com/viewthread.cfm?qid=1663396&page=1> as undeliverable if they exceed 10 MB in size.) 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? The error message I get from exchange is: This message exceeds the maximum message size allowed. Microsoft Exchange will not try to redeliver this message for you. Please make the message smaller -- by removing attachments, for example -- and try sending it again, or provide the following diagnostic text to your system administrator. The following organization rejected your message: {POSTFIX_SERVER.OUR_DOMAIN.com. Thank you, Joel Roberts Network Administrator Joel, Prove it's Postfix that's rejecting your downstream mail. Show the Postfix logs; the eventvwr log from Exchange or the log of you following the Postfix author's suggestion of a telnet session and its output. Did you check Curtis' suggestion too (that it's the Exchange Server that requires configuring also)? -- Mark Homoky. Sent from my iPhone
