Well we’ve narrowed down the issue on our missing emails. After running wireshark we have found that some clients do not follow qmail’s requirement to use a /r/n instead of /n for subject and or body text.
Qmail advocates say that it’s a standard and all should follow (but only qmail does) http://cr.yp.to/docs/smtplf.html
Others advocates say:
“The qmail document refers to a document it calls “822bis”, which apparently was an older name for RFC 2822. Section 2.3 of this document does indeed prohibit the use of bare LF characters within the message body. However, this document is not considered a standard; to find a standard relating to email transfer we must look at RFC 822, also known as STD 11. RFC 822 does not specifically prohibit the use of bare LF characters in message bodies.”
But ultimately I’m stuck because qmail is not sending an OK because it doesn’t like the message and the message just hangs there, never processing through the queue.
The problem is our previous system based on EXIM gladly accepted mail from these clients so I’m being forced to rip out IW and go with another solution… unless someone has a fix… and fast!
Thanks to IW support for leading me through this journey. My IW license reseller wouldn’t even open a ticket for me. Goes to show, buy from IW directly if you want quality support.