CF8 Hidden Gem: CFMAIL auto-generated message-id uses specified mail server name
Note: This blog post is from 2007. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.

Some have lamented that in CFMX 6 and 7, it instead used the name of your server where CF is installed, which might be something like "server1" or "bingo", as in:
This might cause a recipient mail server to flag the mail as spam, if the mail server was a different domain name (like "yourcompany.com"). The bummer was that many found no way to fix this. Sure, in CF5 you could set it in a CFMAILPARAM to set a mail header, but CF 6 and above ignores that.
So the good news is that CF8 now does use that CF Admin or CFMAIL SERVER value to create the message-id. If I use CFMAIL SERVER="mail.carehart.org"..., for instance, I might get something like:
What about CF 6 or 7?
But what if you're on 6 or 7? Well, there's a solution for you, too, by way of a tweak in the CF startup script (jvm.config) or (less preferably) in code. Since the change for CF 6 or 7 deserves some explanation to do it justice, I'll take that up in a part 2 message next. I'll also lay out the whole problem with the auto-generated message-id and why it's a concern for some.
For now, I just wanted to get this word out to those who understand the problem already that CF8 solves it. Woo hoo.
http://carehart.org/...
This seems to be HUGE problem to me, because I had always used the IP address of the mail server that I wanted CF to use through the CF Admin. I had only actually set the SERVER property in CFMAIL a few times, and even then used the IP address.
For someone using servers behind a firewall (which I hope is most people!), you ended up with something like 192.168.1.3 as the portion after the '@', and that seemed to be very quickly picked up as a SPAM-related IP address!
It really is a more significant setting than most people probably realize and I think Adobe should say something about it!