Hi Travis, I have the same problem. Attachments included in mail, and received on mail servers like Google, Yahoo, etc. But there are some mail servers that doesn't recognize the attachment - these are the servers that don't identify attachment MIME type automatically (by file name extension, or by its content).
I found in debug mode that MIME type of attachments isn't set correctly by SEAM mail. I set it to application/zip, but debug window shows application/octet-stream. I think this is the core problem, why attachments are not recognized by some mail servers.
It would be helpful if anyone know some solution or workaround for this problem.
I use SEAM 2.1.1 GA, i have tested also new mail.jar and jboss-seam-mail.jar from SEAM 2.2.1.CR1. App server is JBoss 4.2.2 GA.
I'm having exactly the same problem. Have you had any luck with this?
In case anyone is still suffering with this problem - an upgrade to Seam 2.2.2.Final fixed the issue for us.