KMail & server password

If I'm overlooking the obvious, just slap me around... By preference, my outgoing messages are sent immediately, rather than held in the outbox for manual mass sending. Whenever I send a message (via SMTP server), I'm prompted for password. Is there a way to have my password remembered for the duration of the current session, only? I prefer to re-authenticate at the start of each session, but it's a bit much to re-enter the password for each sent message. . I didn't see anything in the Settings menu (I thought "Security" would be the place for stuff about passwords...), but I'm known for missing things that are right under my nose... it's a big nose... casts a deep shadow... :-) /kevin