I have been fighting a problem with e-mail from my Jumpbox (Mediawiki) for over a year now. Problem was e-mail would send just fine to my gmail account, but would never send to my company e-mail (hosted by Intermedia) They would just seem to disappear.

I had played around a couple times with authenticated e-mail, but never quite got it to work. Found the new wiki page on setting it up, and was going through the steps when I found setting that made everything happy.

Problem ended up being that my e-mails ended up having:

Return-Path: www-data@wikiname.localdomain|

@wikiname.localdomain couldn't be found by the mail server and therefore was rejected.

The solution (without authenticated e-mail) was:

sudo nano /etc/postfix/main.cf
add line: myorigin = realdomainname.com

Not sure how to make it fit, but seemed like something good to share for:
http://wiki.jumpbox.com/doc/runtime/faq/send_email

At least something to try just short of setting up authenticated e-mail.

Thanks for a great product!