Ok, I dont have a quick answer for you, but I suspect that the sender will
have to turn up logging on their end as well as manually telnet to you in
order to try to figure out exactly which command Exchange doesnt like.
> Exchange 2000 Version 5.0 Build 2195 Service Pack 2
> >-----Original Message-----
> >What version and SP of Exchange are you running?
> >> How do I solve error 5.3.3 Unrecognize command.
> >> Someone(outside) send mail to me but I can not receive.
> >> It return error message to sender.
> >> SMTP error from remote mailer after end of data:
> >> host hostname[ip address]: 500 5.3.3 Unreognized
> >> Please help me.