starttls problem with smtp virtual server

Hello,

So I have an exchange 2003 install (on a windows 2000 machine, which I
believe to be the root of all my problems), and it has 2 virtual smtp
interfaces, each with its own internal ip. One is for people to use
when out of the office, the other is for internal use and conectivity
to the smart-host. Out of office emailing is accomplished via owa, or
imap+smtp. Lastly, the exchange server exists as a domain controller in
the domain that all the users are also in.

Now heres the problem. Starttls does not seem to work from machines in
the domain.

When you hit the smtp interface from the outside, from a machine not in
the domain the exchange server is in, or a unix machine within that
domains subnet:
ehlo
250-mail.xxx.xxx Hello [xxx.xxx.xxx.xxx]
250-TURN
250-ATRN
250-SIZE 41943040
250-ETRN
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-8bitmime
250-BINARYMIME
250-CHUNKING
250-VRFY
250-TLS
250-STARTTLS
250-X-LINK2STATE
250-XEXCH50
250 OK

But from domain servers you get:

ehlo
250-mail.xxx.xxx Hello [xxx.xxx.xxx.xxx]
250-TURN
250-ATRN
250-SIZE 41943040
250-ETRN
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-8bitmime
250-BINARYMIME
250-CHUNKING
250-VRFY
250-TLS
250-X-LINK2STATE
250-XEXCH50
250 OK

No starttls.....


I find this disquieting, and I have already spent many hours seeking an
answer.

thanks.

.