I have an application that emails results to customers..
sends about 150,000 emails per month. I use CFMAIL in CFMX7 to
create a multi-part email (text and HTML using cfmailpart). I am
finding that a large number of e-mails we send are returned. I
initially thought that they were being returned from the recipient
server because of the error in the message in the e-mail which says
"UNKNOWN USER" .
In doing futher investigation of this problem I have found
that those e-mails are ending up the the Undeliverable folder in
the CFMX\Mail directory. My understanding of that folder is that
items which are unable to be handed off to the mail server end up
there. If that is the case and the e-mail server is available then
what would cause an e-mail to end up in that folder?