Outlook 2007 takes a long time to download E-mails

A common problem that Vista users face is that when they are downloading an email message from a POP3 server, MSOffice Outlook 2007 takes a long time duration to download the e-mail. For instance, a simple e-mail of size 1MB might take up to an hour to download to Outlook 2007.

According to Microsoft, the root cause of this problem is that one of the network hardware devices (which can be the router for instance) is not compatible with scaling of the TCP window size. However, Windows XP does not have this problem – and it is reasonable to assume that the problem is arising from an improper deployment of the window scaling feature of TCP.

Disabling of Vista’s AutoTuning can provide a simple resolution to this problem. This, in fact, is the solution to most of the network problems that are common in Vista. The following steps will guide you to disable the AutoTuning feature in Vista.

  1. Open a command prompt with administrator privileges. [You can go this by going to Start -> All Programs -> Accessories, right-clicking on the Command Prompt, and then selecting the Run as Administrator option.]
  2. Select Continue at the User Access Control prompt.
  3. Enter the following command at the prompt:netsh interface tcp set global autotuninglevel=disabled

  4. Exit command prompt.

Microsoft also recommends that users facing this problem with Outlook should subsequently pinpoint the exact hardware piece that is incompatible with window size scaling in TCP, replace it with a newer piece and re-activate the AutoTuning function.