Email client programs

[Curtis Vaughan <curtis@npc-usa.com>]

I know this is not a windows list and I have never yet asked a question 
like this on here before, but perhaps there is someone who knows the 
answer to this question.

Because our vessels have to get mail over lines that are rather shaky, 
we would like them to pull mail in a way whereby once they've received 
a message it is considered downloaded.  Earlier we were using ccMail 
(Lotus) which did just that.  But now we had them switch over to 
Outlook Express. In the case of Outlook Express,  however, let's say 
they received 3 letters and then the line broke.  Well, when they 
reconnect they would have to get those 3 letters again, prior to going 
on and getting the rest.  Maybe this is just the way POP3 works.  Or is 
there a mail client program that acts otherwise?  i.e., Mozilla, etc.?

Curtis Vaughan