In order for an Outlook client to establish proper communication with an
Exchange Server, it needs to use TCP/IP port 135. This means that TCP/IP
port 135 has to be enabled on all routers (and firewalls) in a packet's path
for RPC communication to work. This condition cannot always be ensured
because several routers on the Internet disable TCP/IP port 135.
Mapi Client connections such as Exchange Clients and Outlook Clients connect
to the Exchange servers over Port135, if the port is now secured over the
internet it is not possible to connect using Mapi from this location
There are many alternative ways which can be secured to connect to the
Exchange server, eg. using Pop3, Imap4 or Outlook Web Access which your
users from the internet can now use to connect to the Servers.
> I would talk to your ISP and see what they have done as
> mentioned in the other replys.
> >-----Original Message-----
> > I run a exchange server 5.5. I applied the blaster worm
> >patch to the server and now my outlook users cannot
> >connect to the server. My internal outlook uses can. is
> >port 135 lock out from the outside world somehow???