When deleting a kolab account, the corresponding smtp configuration (have no better terminology for it ... whatever is listed in the "Configure Transport" action from the composers Action flap) remains. I had the impression that it even might stay marked as _default_ transport. Observed in 4:4.5~20100920.1177660-1maemo1.1177547 .
Changing prior to normal, though this is probably quite annoying while testing, this doesn't affect the normal use case that much.
After discussion with Volker and Bjoern Ricks it was decided to close this bug as invalid. Reason: Even though the Kolab wizard creates an SMTP account, sending and receiving accounts are separate "things" managed separately. It would be considerable effort to implement a feature like this and is considered out of scope for the KOMO project.
I cannot agree from a user-perspective and will thus not close this issue myself.