Hosted Orgs, Notes mail routing w/ Cross-certified org

I’ve scoured this forum & saw lots of “close hits” but nothing that is the exact problem I’m having. We’ve setup hosted organizations (Org1, Org2, Org3) in our domain (server name is Server1/OurDomain). Additionally, we route mail & replicate with a completely separate organization. So, in order to accomplish this all, I’ve cross-certified OurDomain with TheirDomain. The problem we’re encountering is that, when we send mail to them (Notes to Notes), they receive it OK but the reply to gets hosed on their side. I see that my message to them looks like it came from User Name/Org1@OurDomain and when they attempt to reply, it gets to our server but then fails with user “not listed in domino directory” because it can’t find User Name/Org1@OurDomain. What am I missing? Why is OurDomain getting included when it’s being sent to them? And, if that can’t be changed, how can I configure OurDomain’s domain docs (I swear I’ve tried every combo on adjacent/nonadjacent b/c I’m not real clear on OurDomain vs Org1 as it pertains to domain docs).

Any help would be GREATLY appreciated!

Thx,

Sharon

Subject: Hosted Orgs, Notes mail routing w/ Cross-certified org

Since I haven’t received any responses, maybe I should just be asking if anyone is running in xSP mode, successfully cross-certified with an external organization (not another internal hosted org), is routing notes mail & successfully receiving replies from the external organization. If so, maybe you can shed some light on how you have this configured (xcert level… i.e. server vs hosted org, connection docs since domain is throwing me off).

Thanks,

Sharon