Gnus: using different e-mail addresses for different groups

[Mathias Dahl]

I use Gnus to read news from two sources. One source is the
internal news server where I work and the other is at
news.individual.net.

Now, to avoid spam to my e-mail address at work I use my
"trash" address on hotmail (the one you will see in this
posting). Works quite well, until someone at work decides to
reply to me and not the group. The reply will arrive at the
hotmail address, and I do not want my work e-mails there.

Can I train Emacs to use a different e-mail address for
different groups? Right now Gnus gets the value from the
user-mail-address variable.

/Mathias