77253 perl smtp error

I am getting an error installing a public gateway page generator it sends the created gateway pages in a zip through the domains smtp server, I am getting this error Software error: Local user "admin at [login to view URL]" unknown on host "[login to view URL]" Its seems to be failing because it is seeing the recipient email as being a non local user on the domain. I either need a sollution or the routine written to utilise sendmail instead of smtp. a quick job for the right person, pay via scriptlance.