Test if SMTP is blocked from Workstation to Internet
We had an issue with a trojan/virus infected PC generating e-mail from it over our network. Our IP as a result got blacklisted. Since then we pulled the PC off the network, and believe the issue to be isolated. As a precaution I blocked all outgoing SMTP traffic to the WAN except our e-mail server. How can I test a workstation to make sure that SMTP is being successfully blocked?