My imap clients query kwallet for their passwords right after login (driven by kmail?). Then when I start Kontact (in which kmail is activated), it queries kwallet also. Frequently, if I give the imap clients access to kwallet followed by Kontact, I get imap errors from the imap servers about "too many connections".

If I deny kwallet access to the imap clients (cancel the dialogs), and give access to Kontact, everything works fine. How can I prevent the imap clients from starting before they are run by Kontact?

I found it. You have to set the accounts' Retrieval Option "switch offline when closing kmail".