Outlook is starting to receive and send mails in duplicate and triplicate

Question

A friend of mine has been using Outlook for years and all of a sudden many of his mails to me and others are being received as duplicate, and he reports that mails that he receives are arriving as duplicates or triplicets.

Has anyone ever experienced this or know what could be causing it?

Answer 1

Prevent & Remove Outlook Duplicates

This page contains answers to common problems about Microsoft Outlook duplicates, where they come from, and how to avoid them. All of the information contained pertains to Microsoft Outlook, not Outlook Express.

This page is broken up into two parts, how to prevent the duplicates from occurring in the first place and how to clean up the duplicates.

Answer 2

Try disabling any outbound mail scanners like Norton Antivirus.

Some outgoing scanners can cause the email program to think that the timeout has been exceeded - and thus, the email client will try transmitting the message again.

Failing that, you can try increasing the timeout of his outgoing server.

This also would apply to incoming mail servers.