Version:           1.9.1 (using KDE 3.5.2, Kubuntu Package 4:3.5.2-0ubuntu18.1 dapper)
Compiler:          Target: x86_64-linux-gnu
OS:                Linux (x86_64) release 2.6.15-27-amd64-k8

It would be superb, if kmail could:

have an option to choose a delay - a time after the messages in "outbox" should be sent.
It could be up to the user whether to turn it on or off.
Default: probably off - that is - 0 delay.

Why?
Many times it happened to me to find a mistake (for example choosing the wrong identity) _while_ sending mail. Sometimes I manage to "catch" the mail while being sent (during the SMTP job) and sometimes not. If the mail could wait a minute in outbox before being sent, then one could catch it :)