Evolution broken

[Noel James Bridge]

Without any apparent reason, Evolution has suddenly become unable to 
send or receive messages. I set up Thunderbird instead and that works 
fine. However, it downloaded about 3500 messages that should have been 
deleted, so it looks as though there has been a problem for some time. 
Webmail shows that the messages have now been deleted but Evolution 
still has the Send/Receive button greyed out.

Anyone else had similar problems?