RouterIgnoreForeignSMTPDomains=1 (on) -> Revert to pre-R5.03 behavior. Foreign SMTP Domain documents will be used only if SMTP external is disabled in the Server Configuration document or as a last chance effort if we cannot find a route to the destination
RouterIgnoreForeignSMTPDomains=0 (off) or variable is not specified in the notes.ini file -> Default R5.03+ behavior. Router will now use Foreign SMTP Domain documents when determining a route to the destination domain. This allows customers to specify a "relay" per Internet destination. Note: If the corresponding SMTP connection record does not contain a relay host, the router will check to see if there is a relay specified in the server's Server Configuration document, otherwise the source server of the SMTP connection record will use DNS to resolve the next hop (traditional SMTP routing algorithm)
Note: This change will affect only customers with an R5.x server with SMTP External enabled and Foreign SMTP Domain documents in the Domino Directory who got used to R5's behavior.