
You'd best only use...
the local machine for outbound machine made mail.
I'd create the accounts and the aliases for those accounts first, swap the MX record and have it slurp up the folders and mail after they start using GMAIL and the authenticated SSMTP port 465 for client outbound mail. 25GB of mail in Google mail is hyarge... I mean... I;ve got 5 years of systems e-mail (a lot) and I'm only at 8GB...
Anything else, just use GMAIL, since it does the "put in sent mail" thing automagically.
In your SPF records make sure the local machine is listed as an allowed machine, along with Google's stuff.
You love it.
And yes, the web interface/dashboard is quite completely well done. Huge orgs are now using it and most have good things to say about it.

Edited by
folkert
March 20, 2012, 11:06:18 PM EDT

Edited by
folkert
March 20, 2012, 11:12:57 PM EDT