change SMTP-list

Hi,

I seem to have two conflicting SMTP-servers in my SMTP-list with the same name.

I get the following message (in Dutch), when I try to change something in one of the two:

So I try to delete one of the two out of the list with the minus-sign -, seems logical, doesn't it? But whenever I try to do that, I get the above message every time again. Now I am in a deadlock.

How can I remove a conflicting SMTP-server with the same name as another one from my SMTP-list?