"Christopher M. Bailey" <chris@chrisbailey.au.com> writes:
this is for hosting emails for corporate customers [...] most are using M$ Outlook as their main MUA, but I'm needing a nice web based one for when they are not in their offices.
Then IMO you're screwed; there are no "nice" webmail MUAs -- at least not nice in the sense that chucklehead management types mean it. If they have smartphones, you could encourage them to use an IMAPS-backed MUA on them. I am also given to understand that outlook sucks at IMAP, which is why all the for-profit groupware suites charge for their MAPI servers or outlook connectors. Since all the groupware solutions suck, I would also be encouraging your management types to use tbird or similar. Another alternative is of course somethiny SaaS-y like "gmail for business" or whatever it's called.