A bunch of topics were mentioned here, so let me take them one at a time:
IMAP Support:
I would equate IMAP to Macintosh computers...not heavily used, but the ones that do seem to fanatically love it in most cases. It's more difficult to support due to disk space issues, as well as the fact that the IMAP protocol causes more drain on a CPU than 'normal' POP3. I'll mention IMAP support to our marketing and leadership groups tomorrow as it's not gotten much love in the past, so to speak, and we're doing a lot of great things with email lately so that may be a nice feature to add on the website (after the SM4 upgrades I'm guessing).
Premium Accounts:
Those went the way of the dodo thanks to the new VPS plans. We only included IMAP support for Premium clients because of a coincidence in naming conventions - we called IMAP support "Premium Mail" and we had "Premium Accounts"...so it didn't really make much sense not to support IMAP on Premium Accounts.
Postini Pricing:
That's pretty much the only complaint we've heard from the new Postini offering, and it is a valid one. Unfortunately since Postini is a 3rd party service it's something that we get charged for. We pay a base cost per month to have the Postini API, plus we also pay on a per-account basis. If we were to waive all Postini fees we'd also have to drop pretty much every shared hosting plan we have since our clients would basically be able to setup dozens of postini users and as a result cause more charges than they're paying us for. We'd love to do that, but we won't serve anyone very well if we go out of business.
Again I see where you're coming from, and if we could find a way to get the same level of filtering from our own system or one implemented via Smartermail we would, but simply put Postini's methods are first class and not easily matched.
SpamAssassin does come with Smartermail v4, as you can see if you read up on the SmarterTools website and/or have your own installation on your VPS/Dedicated server, however SmarterTools only rates it capable of handling 40,000 inbound messages per day, which is well under what our shared servers handle. Given that, we chose not to support SpamAssassin at all in SM4 and instead went to Postini.
Another fault is the fact that the SpamAssassin ruleset would be stored on each server, and it doesn't update when SpamAssassin comes out with new rules...and if we wanted to put in custom rules or alter ones already there to prevent false positives, we'd have to make the changes on EVERY shared smartermail server - we have over 50 at this time. In short (like I ever do anything in short) it's simply not feasible to support that kind of system in our environment.
If you have a VPS or Dedicated and want to use Postini, have no fear! We're working on ways to implement Postini with those types of accounts and should have something in production soon.
