STMP is rejecting and i'm not sure why

[Dirk Laurenz]

Hello $list,

 

my server rejects an email from certiain domain:

 

<onl...@server.sub.dom.local>: host

    server.sub.dom.local [xx.xx.xx.xx] said: 550 5.7.1

    <onl...@server.sub.dom.local <mailto:onl...@server.sub.dom.local> >:
Recipient address rejected:

    Recipient domain dom.local is not used. (in reply to RCPT TO command)

 

The sender has changed his mail from u...@sub.dom.com
<mailto:u...@sub.dom.com>  to u...@dom.com <mailto:u...@dom.com> 

 

What's going wrong here?

 

Regards and thanks for your help

 

Dirk