I've developped a new small plugin, "mail auto fetch", that is based on
the SM's standard "mail_fetch".
I did it simply because one of our customers had a need for it.
Namely, the problem for them was that they didn't want to provide an
IMAP server for all the users, as it's very much resource consuming, and
thus keep the main mail server only using POP. Then a separate server
will hold SM & IMAP (IMAP being only used as a local database).
So this plugin just adds a "Fetch Mail" link to the menu, that allows to
pop from the POP server specified in the conf, with the login/password
used to log into SM, and then copy the mails onto the IMAP server used
by SM. No configuration is left to the user. Moreover, it is a lot less
verbose than the original plugin (the user certainly doesn't need to
know all the details...). It uses only localized strings from mail_fetch.
It also includes a small optionnal filter for SPAM messages.
Now i guess it could have been developped as an heavy set of options to
put over "mail_fetch", but i really didn't have the time to do that. Or
also we could have inveted something using fetchmail...
Still, it's GPL. So if someone's interested, it's there :-)