[IMP] excessive POP3 sessions??

[Roger Kam]

Dear all,

I've successfully installed Horde with IMP in my system.  It's seems to
work find.  However, since our email system is still stuck in using POP3
only, I got a big headache concerning the performance issue.

It seems that whatever I do in the web interface, like clicking on a mail
to view its content, delete a mail, going back to the listing, the system
will POP all the mails for that user again.

When I tried with an account with 100 mails, the total number of POP
requests is >400.  And all I did was login, viewed the content of one of
the mails, deleted it, and went back to the listing.

For the sake of arguement, let's assume I have 50,000 users, each of them
have 50 mails in their mailboxes, and all of them login to check mail just
5 times a day, each time just viewing 5 mails and deleting 2.  That would
mean having 125 million POP request per day.....  That wouldn't be quit
reasonable, would it?

Can anyone briefly explain why this would happen?  Is there anything I
might have missed out?  Are there any ways to improve this?

Thank you very much for your attention.  And I'd be very grateful if
someone could sheds some light on this for me.

Best Regards,
Roger