1) Always state your version of Outlook and the type of account you're
using.
2) Disable any antivirus or -spam product that integrates with Outlook. You
may have to completely uninstall it and reinstall without the mail scanning
option to truly disable it.
3) Increase the server timeout value on the Advanced tab of your account
properties page.
4) Increate your send/receive interval to at least ten minutes.
