Connection timeouts - sending

Hi,

Have had this message quite a bit recently ..

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Sending failed:
The message content was not accepted. The server responded: "Connection 
timeout, try later" This is a temporary failure. You may try again later.
The message will stay in the 'outbox' folder until you either fix the problem 
(e.g. a broken address) or remove the message from the 'outbox' folder.
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Now, I know this is a server problem, not a KMail one, but how do I set the 
timeout in KMail please ?  I obviously need to make it much higher.

Thanks,

Peter