The mail system on kerouac is very simple, offering a fairly standard set of hosting services using Postfix. Mailing list services are also avaliable, provided using Ecartis, as is UUCP forwarding for domains.
Mail may be read locally using any of the installed mail readers or remotely using SSL tunnelled IMAP or POP3 served using Courier IMAP. If a standard Unix mail reader that you'd like to use is not installed please just ask for it to be installed. Several filtering tools are installed including procmail and mailfilter.
Please note when filtering mail for access via IMAP that Courier uses a slightly eccentric system for naming on-disk folders: '.' is used as a directory seperator and folders are located in Maildirs within INBOX with a leading '.' in the name. This means that if you have a folder called a with a subfolder b it is stored in a Maildir in "~/Maildir/.a.b". Folder a may or may not exist.
Spamassassin is installed on the system and is running in daemon mode. It can be invoked from mail filter scripts. If you are using procmail then this stanza will filter all e-mail through spamassassin:
:0fw: spamassassin.lock
| spamc
and this untested example should cause it to filter anything it determines to be spam into the IMAP folder INBOX.spam:
:0:
* ^X-Spam-Status: Yes
~/Maildir/.spam/