Is your antivirus integrated with Outlook? This is a common symptom. If your
antivirus is configured to actively scan outgoing/incoming emails, you will
often see this problem.
Check your services console to see if there's an email scanning service that
you can temporarily disable to see if this changes the undesired behaviour,
or simply open Outlook in safe mode (which disables all integration):
Windows Vista & 7
Start > Start Search> outlook.exe /safe
(note the space between outlook.exe and /safe)
Windows XP & older
Start > Run > outlook.exe /safe
(same space, same place)
"slim" <firstname.lastname@example.org> wrote in message
> When I reply to an email the recipient will receive 2 copies of the reply
> email. Using Outlook 2003.