I would be EXTREMELY surprised if this is down to qmail!
Have you posted your question on an Outlook newsgroup?
Cheers.
Philip N. Han writes:
>
> Hi,
>
> We have over 800 members and sent out newsletters using the Bcc function
> within Microsoft Outlook via qmail server.
>
> Up to three weeks ago everything worked fine then we started to get a few (3
> or 4) return e-mails telling us that all the email addresses were showing up
> in the body portion of the e-mail message. And, in some cases attached files
> do not arrive.
>
> I checked all settings in Outlook and even reinstalled the program but this
> did not solve the problem.
>
> The question now is - could the problem involve qmail server?
>
> We just installed qmail scanner from http://qmail-scanner.sourceforge.net/
> .
>
>
> Thanks for any help.
>
>
>
> Philip N. Han
>
