Inconsistencies connecting to Exchange 2007

Question

Greetings:
We have just migrated a high-demand client to Exchange 2007, and are using a combination of Apple Mail and Entourage for a few different users.
Users are reporting messages coming into their Blackberries and Entourage almost immediately after sending.
Yet in Apple Mail, we are seeing issues where some of the mail is not being received by Mail for sometimes up to 30 minutes later.
We're trying to nail this down to see if it has to do with certain messages that use attachments. It has been difficult to reproduce, but we've had many complaints in the last 2 weeks since we made the switch.
Additionally, when we were on Exchange 2003, two of the users liked using POP because of the sheer number of messages and attachments they received. On the new server, POP became impossible to use because Apple Mail would start downloading the same messages two, three, sometimes even four times, causing massive amounts of duplication.
Attachments haven't been consistent in Mail. I will sometimes see messages via OWA that have the attachment, but Mail will not show the attachment. We are having users quit Mail and restart it, and sometimes this can correct the flow of messages, as well as attachments showing up or not.
There is another issue that has been plaguing us: at least 2 or 3 times in the last couple of weeks, someone has deleted a message by accident. And when going into the Trash to find the message (Mailbox behaviors are set to store deleted items on server), the message has just disappeared. They've been able to pull it from the Blackberry in some cases, because Mail does not always resolve the deletion quickly.
We wanted to know: what are the caveats of using Apple Mail with Exchange 2007? Does the newest rollup make all the difference? Are there issues that we should know about? The "slowness" issue is the biggest complaint we're getting on a regular basis.
Internet connections vary, since the principles of the company are spread out between Hollywood, Palm Springs, and Tulsa - and the reports we're getting back are coming from all of those locations.

Answer 1

The first thing to check is how often Mail is polling the server for new messages. Mail does not support Push messaging from Exchange, so you have to set the frequency of message checking appropriately. I have mine set to check every minute.
I can't address the issue with attachments, though we have had similar problems with Outlook clients that have turned out to be problems with the user's Exchange profile (Blackberry systems use RIM's own mail servers, not the Exchange server, so you can't really compare experiences there). For deleted messages, there may be more than one folder in which deleted messages may be put, so it may be that your users just aren't looking in the correct folder; there may be the Mail Trash, but also a Deleted Items folder down in the list of folders.
Hope this helps.