Outlook 2007 has a number of issues with performance, one of which relates to downloads taking a very long time with POP3 email accounts. Microsoft has recently published a KB article that should fix some scenarios where this occurs, specifically on Windows Vista, which may be caused by network hardware device(s) that do not support a networking feature called TCP Window Scaling.

The short version of this is to run this command as administrator and see if it helps your situation any:

netsh interface tcp set global autotuninglevel=disabled

If not, then probably your Outlook 2007 performance problems have other causes (of which there could be many), but this is worth a shot and known to greatly improve performance in some cases.

Read the complete KB Article here.

Tags: Outlook+2007