[gentoo-user] [OT] IMAP4 behaviour

[Mick]

I have noticed that the bandwidth consumed by an IMAP4 account of mine is 
rather high and I believe this because of the following type of behaviour:

I click to send the message.  The message is uploaded to the server.
I click to sync/receive messages.  The message is uploaded again(!) to the 
server this time in the sent-mail IMAP folder.
I delete the message.
I click to sync/receive messages.  The message is uploaded again(!) to the 
server, this time in the Trash IMAP folder.

Shouldn't it move from one folder to the other on the server instead of it 
being uploaded afresh from my desktop?  It strikes me like a waste of 
bandwidth.  Is this a typical IMAP4 server implementation, or should I be 
having words with my ISP?
-- 
Regards,
Mick