internet/x400 addresses

[bip]

strange problem (for me anyway)

Scenario

Emails have been bounced back by several local sites, turns out these sites use x400 internally but advertise smtp addresses. When I try and email users via their x400 address it works. I’ve been told that something on site is stamping our smtp emails with our x400 address, which is then confusing the local smtp\x400 email gateway.

Question

Is smtp email been stamped with x400 mail addresses somehow?

x400 emails are sent via the x400 nlm thru a net-tel gateway

smtp emails are sent via gwia and mailsweeper

as a temp fix I've shared an address book of x400 addresses

Any help would be appreciated as i'm now stuck.


Thanks

Bip.