POP Spam problem

[fitfixer]

while all our domain users use SMTP mail, a number of external stand alone mail users use pop to connect to our Exchange 2K3 box, Outlook is set to both send and receive to an address that I setup; pop.<ourdomain> with a DNS pointing at one of our public IP's and a port forwarding rule at the firewall, this has worked fine for 3 years

But now spammers have discovered this and each day I watch the mail queue filling up with spam, the pop server is set to anonymous authentication because the users do not logon to a domain

How can I close down this hole? I imagine that they are using the SMTP connector to relay
I would be grateful for any suggestions

Thanks in advance

FrankF
A+,Network+,MCSA

 

[58sniper]

Ideally? Implement RPC over HTTPS for the remote users, and kill off POP.

Also, configure related IMF settings.

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[fitfixer]

Thanks for your reply Pat,

This was setup before RPC over HTTPS was a practical option, there are about 150 users and it will take time,I guess what I want is a quick fix to buy some time to allow a gradual migration to rpc over https,

Best Regards

FrankF
A+,Network+,MCSA

 

[58sniper]

take time? 1/2 an afternoon maybe......

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[fitfixer]

changing over 150 remote clients is a big job for field technicians, some customers would need an on-site callout, some could be done remotely, all would require their PST to be migrated to the new profile, realistically you are looking at 4 weeks


FrankF
A+,Network+,MCSA