imap-server an IMAP mail server
mail-reader a mail user agent (e.g. Pine, Elm, mailx, &c)
mail-transport-agent a mail transport agent (e.g. Smail, Sendmail, &c)
+ mailx a /usr/bin/mailx binary (*)
news-reader a news reader (e.g. trn, tin, &c)
news-transport-system a local news system (e.g. INN, C News or B News)
pgp a version of PGP (International or US)