OT: Linux Mail Server

[Pete russell]

I know this is off topic, but a wide range of experts here, is too good
an opportunity not to try and get some useful info.

I have to replace the Lotus Domino server with a free Linux solution
that currently provides 300+ users with email. We hardly use any
calendar/scheduling or to dos etc. The aim is to recover the expensive
Notes licenses for use elsewhere.

The users only require webmail access to email and address books
(private and public).

We require quotas per user, easy admin UI to allow casual helpdesk staff
to admin accounts and password changes who are not Linux savvy.

I know I can use most any webmail UI, eg horde or suirrelmail or
neomail.

Does anyone have preferences, advice or suggestions for a particular
mail server? And or message format? Eg maildir or mbox?

Anyone ever tried to convert Lotus Notes mail DBs to either maildir or
mbox? I figured I would look at fetchmail or similar and grab all the
mail out that way? Just need to figure a way to not reset the date on
each message.

Love to hear any suggestions.

Thanks again
Pete