I have the option checked to keep the .spamassasin folder cleared but I noticed these files with 'expire' added to them and wondered if they could be safely deleted.
Directory Space Used
.spamassassin 15.22 Meg
.spamassassin/bayes_toks 3.83 Meg
.spamassassin/bayes_toks.expire2581 3.33 Meg
.spamassassin/bayes_toks.expire9352 2.84 Meg
.spamassassin/bayes_toks.expire5530 2.44 Meg
.spamassassin/bayes_toks.expire4252 1.30 Meg
.spamassassin/auto-whitelist 1.02 Meg
.spamassassin/bayes_seen 0.30 Meg
.spamassassin/bayes_toks.expire7299 0.07 Meg
.spamassassin/bayes_journal 0.05 Meg
.spamassassin/bayes_toks.expire9403 0.02 Meg
.spamassassin/__db.bayes_toks.expire1580. 0.00 Meg
.spamassassin/user_prefs 0.00 Meg
Directory Space Used
.spamassassin 15.22 Meg
.spamassassin/bayes_toks 3.83 Meg
.spamassassin/bayes_toks.expire2581 3.33 Meg
.spamassassin/bayes_toks.expire9352 2.84 Meg
.spamassassin/bayes_toks.expire5530 2.44 Meg
.spamassassin/bayes_toks.expire4252 1.30 Meg
.spamassassin/auto-whitelist 1.02 Meg
.spamassassin/bayes_seen 0.30 Meg
.spamassassin/bayes_toks.expire7299 0.07 Meg
.spamassassin/bayes_journal 0.05 Meg
.spamassassin/bayes_toks.expire9403 0.02 Meg
.spamassassin/__db.bayes_toks.expire1580. 0.00 Meg
.spamassassin/user_prefs 0.00 Meg