How to fix slow Outlook IMAP folder synchronization issues

EQ Admin

EQ Forum Admin
Staff member

To speed up the synchronization time for subscribed IMAP folders in Microsoft Outlook:
  1. Go to to Send/Receive, then Send/receive groups, and define send/receive
  2. On the right side of the send/receive groups window click on the Edit button
  3. Uncheck the "Get folder unread count for subscribed folders"
  4. Under Received mail items check the option "Use the custom behavior defined below"
  5. In the next window below select INBOX and leave the other folders unchecked
  6. Click OK and then exit out of your options
  7. Do a send/receive to verify your Outlook is faster now
You may also want to increase the mail server timeouts in Microsoft Outlook.
Last edited:

Nirav D

Thanks Ray for the info. But I appreciate if u can actually explain the logic.

(1) What does "Get folder unread count for subscribed folders" actually mean? What difference does it make if we leave it checked or unchecked?

(2) If we select Inbox only and if one has set up auto filtering rules then will the new email be downloaded in respective folder?


New Email
Hi There,

This worked fine for one of my machines, but on my MS Surface (Win 8.1 Outlook 2013) I don't have a check box next to the Inbox icon. Is there a way to fix this?

Many Thanks


New Email
Hi popowich,

I am using the outlook auto filter tool, which moves new emails into subfolders.

If I uncheck the "Get folder unread count for subscribed folders", yes outlook become faster to sync emails, but the problem with this is that outlook doesn't check for new emails in the subfolders any more. I have to click on a subfolder to check for new emails in it.

The better approach for me is:
tick "Get folder unread count for subscribed folders",
Under Received mail items check the option "Download headers for subscribed folders".

This way, I will be notified of new emails faster, and then selectively download the body of new emails.

I am still looking for better solutions.

Hope it helps.
Last edited by a moderator:


New Email

Just to let you know what I end up with to solve the slow outlook synchronization issues.

My solution is: use a better email client! I recommend Thunderbird after testing a few others.

I have been using Thunderbird to handle 10+ email accounts for a couple months now. I am very happy with it, love all the option it give me to control my email accounts and the ability to install add-ons. The most important thing is that no more waiting to sync emails.

Hope it helps


New Email
Thankyou Popowich, Perfect, fixed my now office 2016 imap issue.
I believe this works well because my folder rules are processed on my local machine, so i don't need to know if something has changed in the other folders.