Blocking external email accounts

[imported_JFG]

We want to implement a policy where users can't access external email accounts. Seems the only way to do this is by rules in the firewall blocking URL's. Does anyone know of where I can get a list of known email sites. Obviously we can't get them all, but maybe like the 100 most popular.

Thanks

 

[JRock]

Rather then even attempt to even do this why no just start a whitelist? ONLY allow sites needed for production work.

A fairly cheap device that has features for this as well as a some others is the Cymphonix Network Composer.

Contact them or your reseller for a demo unit. We got it on demo and found it quite useful for the cost.

 

[imported_JFG]

Believe me, that would be ideal but it would never get approved. It took over a year just to get IM blocked.

 

[JRock]

What kind of firewall do you have in place? Make and Model.

 

[Joemonkey]

You could get a program like Websense, it works wonders for things like this

 

[imported_erikm5150]

http://www.fepg.net/providers.html

 

[Brazen]

Block ports 25 and 110 to/from anything but your email server. We use a Content Filter to block web based email sites. There is no pre-built list for this, we just put in the ones we know.