SimpleMail is a completely GUI-less addon to grab stuff from your mailbox. It runs entirely from simple commands; for instance, "/simplemail -e get" will try to get every expired auction from the mailbox. I wrote it because I have a full-time banker (who puts up insane numbers of auctions) and an enchanter who is funding his career entirely by buying greens and selling mats. Both cases involve receiving a couple hundred messages a day... Most of which, all I want to do is grab the items or money out of the mailbox.
UPDATES:
* User interface subtly changed; syntax is now '/sm [flags] [check|get]'.
* Ranges are now specified with flags.
* More flags.
* Now includes the GetOpt library internally.
* Works under 2.3.
KNOWN ISSUES:
* Sometimes hangs. Try "/sm kick" or run away from the mailbox and come back.