We are the mailbox provider. Sorry if my knowledge and understanding of Postfix is nowhere near yours. I am still learning, and the only way that happens is to ask questions. Your suggestion of arranging a PCAP file, comparing inbound to outbound is something I have never had to do in 12 years of running an email server. Having never done it, I will muddle through somehow.
While my question may have seemed not meaningful, it resulted in a "direction" I can take which is what I was seeking. Jeff On Jun 18, 2014, at 10:47 AM, Viktor Dukhovni <postfix-us...@dukhovni.org> wrote: > On Wed, Jun 18, 2014 at 10:18:54AM -0500, SH Development wrote: > >> I have a customer that is claiming that their customers are >> getting emails without the attachments. > > Anecdotal claims are useless. Some evidence needs to be presented > that the attachment was removed en-route. > >> I can see in the log that the receiving server has accepted the >> message, and the message size indicates there is "something" >> attached. > > Are you a relay in front of the customer's MTA, or the mailbox > provider? > >> We do have a size limit set of 20MB, but usually when something >> is too big, it just bounces it, not drop the attachment, so I don't >> think it's a size issue. > > Postfix has no code to discard attachments. You'd have to do that > with a milter or content_filter. > >> Ideas? > > You've not learned how to ask meaningful questions. Without any > evidence in the form of logs for and headers of a message that is > alleged to have lost an attachment en-route, nothing useful can be > said beyond the observation that Postfix delivers complete messages, > and does not have any built-in facilities for removing individual > attachments. > > If the problem is reproducible, arrange to capture a PCAP file of > an inbound cleartext transmission of the message, or to freeze it > in the hold queue without any processing by milters or content > filters. Then determine whether the attachment is initially present. > Similarly capture cleartext outbound transmission, or divert outbound > transmission to an intermediate relay where the output message can > be compared with the input. > > -- > Viktor. >
