Slow IMAP Outlook

My small business hosts our email with ( / / We use IMAP to keep multiple devices in sync and have many users using different mail programs, Outlook, Thunderbird, Apple Mail.

The latter two work consistently and well, however, we have some stubborn Outlook users. Outlook works well, some of the time. Others, it can take over an hour for messages to come through. When we know messages are on the server but not coming through to outlook and press send/receive that can complete and still messages do not synchronize. Sometimes, the Inbox will say it has unread messages (ie Inbox (4)) but those messages will not appear in the actual inbox (these messages do not necessarily have large attachments, or any attachments). I have set the IMAP folders to be subscribed, and also set the entire messages and their attachments to download.

Again, sometimes it works well and other times has problems (at least a few hours per day). On the same computer with the same email address i can open Thunderbird (when Outlook isn't working) and it will grab the messages with no problem.
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apache09Connect With a Mentor Commented:
See how you get on with the update.
SP1 fixed several slow issues in 2007.

However, if later on you find that its still slow.
Here are a few more tips.

We're seeing many reports of Outlook 2007 being very, very slow. As of this date, we don't know the cause but we do have some possible solutions. Before trying these solutions, install the Outlook Performance update

Solution 1: Rename or delete outcmd.dat, extend.dat, views.dat and frmcache.dat. Outlook will recreate these files as needed.
Look for these files at the following locations in Windows XP and Vista:

C:\Documents and Settings\<username>\Local Settings\Application Data\Microsoft\Outlook

C:\Documents and Settings\<username>\Application Data\Microsoft\Outlook

C:\Documents and Settings\<username>\Application Data\Microsoft\Outlook

C:\Documents and Settings\<username>\Application Data\Microsoft\Outlook

Solution 2: Create a new PST. Although the Outlook 2007 PST is essentially identical to the PST format new to Outlook 2003,Outlook 2007 writes additional data to the PST.

If this fixes the problem, import or move your items from your old PST to the new one.  

Solution 3: Create a new profile. No need to delete the old profile just yet, just make a new one to see if the problem is fixed.
If this fixes the problem, you can delete the old profile.

Solution 4: Disable Outlook Setup Add-in (Instant Office add-in by Cyberlink) on Dell computers that have  Media Direct installed. This add-in is responsible for converting meeting requests to recurring meetings and creating calendar and contact folders when saving attachments. It also slows Outlook down.
Go to Tools, Trust Center, Addins and locate the add-in. At the bottom of the screen, select Manage: COM add-ins and click Go. Remove the checkmark from the Cyberlink add-in and close the dialog.

Solution 5: Uninstall Business Contact Manager
Check for the known issue with 2007 and IMAP

We're seeing reports from a lot of panicked Outlook 2007 users who have IMAP accounts in their profile that Outlook is infected with a new virus because it sends upwards of 50 hidden messages every few days.

It's not a virus, its a bug involving IMAP accounts, the Junk Email folder and Read Receipts. Outlook 2007 is not honoring the Read Receipt settings and returning Not Read receipts when the Junk folder is emptied.

Microsoft is investigating and until it's fixed, mark Junk mail read within Outlook, before deleting it.

Also, check that you have the latest SP installed:

aseismanAuthor Commented:
These are brand new email accounts and therefore (thus far) receive no spam. I have just installed SP1 to see if they continue to have problems today. If they do, do you have any further suggestions?
aseismanAuthor Commented:
While this did not solve the problem completely (Outlook can still, seemingly randomly go hours without receiving mail that is on the server), I am resigned to this is an issue with outlook that MS needs to fix. I believe these steps have made Outlook's performance better, but no where near as good as Thunderbird or Apple's Mail.
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