Mass mailing Virus

[Sl33py]

SAIX has blocked 2 of my clients from sending mail. They were infected with viruses so port 25 was blocked. I have been removing a lot of viruses lately from clients PC. I connect their PC to my network as I have to update the programs to scan their PC.
I can’t receive mail but can send through Telkom’s SMTP, I have a registered domain so use pop3.mydomain.co.za. If I use another adsl username and password to make an internet connection I can receive email. I use my cell phone to check email and that works fine. So I wonder if I am blocked somehow?
So this got me thinking how do I update clients PC without putting myself at risk?
Use a firewall to block all ports and use a mail server to send mail on a different port?

 

[ambo]

If you are working on machines that you know are compromised then ideally you want to entirely firewall them in their own LAN and only allow the required ports and the required update servers.

As a side note you should probably be using the submissions port (587) for sending mail rather than port 25.

 

[Sl33py]

So like IPCOP and have 3 networks, green Red and orange.

 

[ambo]

So like IPCOP and have 3 networks, green Red and orange.

That would work... and put the client PCs into the orange network.

 

[MeNeZ]

You could also make a virus toolkit/update pack and burn it to cd...clean the pcs before you join them to your network. (Use a CD-RW and put on the latest patterns & windows updates)