- "*Non-nil if the mail is to be left on the POP server after fetching."
- :version "21.4" ;; Oort Gnus
+ "*Non-nil if the mail is to be left on the POP server after fetching.
+
+If `pop3-leave-mail-on-server' is non-nil the mail is to be left
+on the POP server after fetching. Note that POP servers maintain
+no state information between sessions, so what the client
+believes is there and what is actually there may not match up.
+If they do not, then the whole thing can fall apart and leave you
+with a corrupt mailbox."
+ :version "22.1" ;; Oort Gnus