[Mailman-Users] mails to lists are passed erroneously to cyrus

[Glen Prideaux]

>> Presumably because the MX for the schwach.de domain in DNS is
>> mail.schwach.de whose IP address is 87.230.26.25 and this is not the IP
>> address of your Postfix/Mailman machine.
>> 
> 
> Thank you. But can you explain the matter a little more.
> 
> schwach.de is hosted by an ISP. The ISP collects the mails with its mail
> server. My machine fetches the mails via POP3. So my machine gets the
> mails. Postfix should control that mails from the domain schwach.de are
> passed to mailman, from other domains are passed to cyrus. Is not this
> controlle by the file /etc/postfix/transport ?
> 
> Egon Frerich

It's a bit hard to be sure from your explanation, but this is what I think is happening.

When you send mail from your machine to v at schwach.de, your machine deals with the mail correctly and it goes straight to mailman. This suggests that if the message gets to your machine it should be correctly handled.

But when you send from another machine, it works like this:
  source machine does a DNS lookup for the MX for schwach.de and finds mail.schwach.de->87.230.26.25
  source machine talks to mail.schwach.de, "I have a message for v at schwach.de"
  mail.schwach.de does not know about the list you have set up on your server so replies "Mailbox does not exist".
Thus the message never gets to your server. The error message does not come from your server, it comes from your ISP's server at mail.schwach.de.

In order to fix this, you need to arrange with your ISP for it to recognise v at mail.schwach.de as a valid address, perhaps as an alias for your regular mail account. 

It may be simpler to register an Internet domain name for your server (perhaps using a service like no-ip.com if you don't have a static IP address) and have the mail delivered directly to your server and not go through your ISP's mail host at all.

Glen