Event notifications recipients restrictions

[ThomasPL10]

Hello all

Can you tell me is there some limitations for e-mail adresses of recipients for event notification?
Let me share with you my example.
As sender address I'm using servicedesk@mydomain.com
I would like to send notification to dedicated e-mail address when priority of the ticket is changing.
When the dedicated e-mail address is someaddress@mydomain.com everything works fine.
However if the address is someaddress@otherdomain.com there is no action of OTRS. I cannot even see in logs that there was some attempt of sending the notification.

Maybe is there some SysConfig setting which restricts such behaviour?

[ThomasPL10]

Just a kick off