FromDomain gets added to mail when user reply a mail they received from domino smtp gateway

Hi

I have a domino smtp gateway which sends mails to another domino server backend…Notes routing - and a connection document enabled.

When a users receives a mail from the outside…and replies to it…@gatewaydomain gets added… and you have to delete that first…to reply…

I have tried foreing domain documents…adjacent domain document…nothing helps… - the router just adds the field FromDomain field to the mail…and therefor this happens…

I will not use smtp routing…it should work with notes routing from domino gateway with antoher domain name than the backend domino domain…without having the extra domain name added to the mail?

have also tried this:

Notes items to be removed from headers…did not help

and ideas?..thanks