Sub Domain not making it out of the local GroupWise environment

[SherpaDave]

I've got an issue where a domain alias is used to foward email to
Google Apps (or Postini actually)... for instance, the main domain is
@domain.com, and the domain alias is @gapps.domain.com. However,
within GroupWise, when we setup the Flat Forward to the
@gapps.domain.com address, the local GWIA still thinks it a local
domain and does not route it to Google, or rather Postini in this
particular case.

The admin is suggesting we need to add the domain alias to the
ROUTE.CFG file, but unsure of what to put in there to effectively
route those emails to Postini (as opposed to Google directly). We
have a work-around, which is to forward to @domain.com.test-google-
a.com, but being that it is routed directly to Google, those emails
are not being Archived in Postini, which they require.

What would I enter into the ROUTE.CFG file to route those
@gapps.domain.com emails to Postini (System 5), as it appears you can
only add one IP address and not a range (or can you)?

Thanks,
Dave