Simple Mail System for Ubuntu – Setup Guide

You will need to use a redirect router. Read the Exim Router specification, as it can do many things and thus can get quite complex.

Basically, you will need to set something up like this (untested)

sender_redirect:
  driver = redirect
  data = ${lookup{$sender_address}lsearch{/etc/exim4/sender_redirects}}

Then create a file in /etc/exim4/sender_redirects that contains the redirects in a line-separated colon-delimited format, like this:

me@example.com: me@gmail.com

1. The sendmail package. No problems with it really, might even be installed by default.
2. # echo "test" | mail -s "test" your@email.com
3. None other then that. Check out the reference page.