[Dovecot] Dovecot-imap, tls, gnus

[Richard G Riley]

I have a connection to my dovecot server from gnus:

,----
| (add-to-list 'gnus-secondary-select-methods
| 	     '(nnimap "hermes"
| 		      (nnimap-stream starttls)
| 		      (nnimap-address "hermes")
| 		      (nnimap-authinfo-file "~/.authinfo")))
`----

If I enter a group and read my mail then wander off and come back after
a few minutes I can not navigate out of the group because my nnimap
session has ended. What config parameter do I need to change in Dovecot
to keep it open for the life of the client? (I am assuming its a dovecot
issue here since it didn't happen with courier-imap).