I have used the same ISP for years - and also for years have used MS Outlook 2003 as the email client via POP3.

After recently upgrading to Outlook 2010, I find that it takes an eternity before new emails will download.

Why?

Hi,

What if we manually click the Send/Receive All Folders button to force a download of emails?

Does it work faster in Outlook safe mode? Do you have any antivirus software installed? If so, please try disabling the antivirus integration with Outlook and then test it again.

Did you use the original PST file from Outlook 2003 in Outlook 2010? If so, I'd like to know how large the PST file is. Please make sure it's not too large. If the file size of the PST file is exceeding the limit, it may cause performance issues and other unexpected issues. If the file size of the PST file is OK, we can try running the Inbox Repair tool (Scanpst.exe) to scan and repair your Outlook PST file to see if it helps. For your convenience:

https://support.microsoft.com/en-us/kb/272227

In addition, this issue may also happen if your network hardware device does not support TCP Window Scaling. For detailed information, please have a look at the following KB article and check if it applies:

https://support.microsoft.com/en-us/kb/935400

Please let me know the result.

Regards,

Steve Fan
TechNet Community Support

Hi,

This type of issues occurs if a network hardware device, such as a router, does not support TCP Window Scaling.

To determine whether this problem is caused by network hardware device that does not support TCP Window Scaling, follow these steps: -

Click Start > All Programs > Accessories.

Right click Command Prompt > Run as Administrator.

If you are prompted for an administrator password of for confirmation, type the password, or click Continue.

At the command prompt, type the following command, and then press ENTER.

        netsh interface tcp set global autotuninglevel=disabled

Close the Command Prompt window.

Restart computer

Start Outlook. If the problem is fixed, you can either keep value for the autoTuningLevel parameter as disabled or isolate the hardware that does not support TCP Window Scaling.

Regards

Hi Steve,

I'll work through all your ideas. Thanks for them (and for your reply too Ashish).

It does just seem to be the initial connection that is sluggish. After that, manual send/receive (hitting F9) works as normal. Yes, my outlook.pst file came from Outlook 2003. It's size is currently around half a Gig.

One other thing I could try is to move all my emails into a personal folder, ditch the outlook.pst file and create a new one from scratch. I might also try creating a second email account from scratch to see if it has the same problem.

An interim report:

The sluggishness only happens the first time after a cold boot or the first time after a restart from sleep mode or hibernation. In each of those cases, Outlook 2010 then takes up to 1 minute to complete its Send/Receive synchronisation with the webmail server.

After that, every Send/Receive (i.e. hitting F9) gets back to normal and completes in about one second.

The problem appears to have been fixed. Anti-virus (MSI in my case) was not involved.

I did the following:

- Reduced the size of outlook.pst by moving a large chunk of emails to a personal folder

- Compacted the outlook.pst file (File / Account Settings / Data Files tab / Double-click the Outlook file / Click on Compact Now)

-  Followed the *.pst repair process as described in https://support.microsoft.com/en-us/kb/272227). It did detect some errors in my outlook.pst file and fixed them.

I'm not clear what was fixed but the sluggish behaviour has now disappeared.

Many thanks for your replies.