On 9 mai 09, at 13:43, Thomas Floeren wrote:

> […]
> I’m receiving the mails via gmail, the client program is the  
> standard AppleMail-program.
> Does anybody have similar issues?
>

Hi Thomas,

I use Gmail and Mail.app on a Mac too, and have been puzzled like you:  
Gmail orders the messages as "conversations" and when you send a  
message with Gmail, when it is sent back to you through the mailing  
list, then Gmail does not deliver again a copy to you… Indeed it  
assumes that you are already aware of it :-)

One solution (which I use) for being certain that your message has  
been received by the mailing list, is to configure your settings at
http://www.ntg.nl/mailman/options/ntg-context/
so that you receive a confirmation message whenevr you send a message  
to the list.

Best regards: OK