ISA firewall mystery has me stumped
Posted on 2006-06-22
SBS 2003 with ISA 2004
4 client PC with XP Pro and Outlook 2003
Three of the four client PC are able to retrieve/send POP/SMTP email using Outlook 2003. We are not using Exchange at this time. Each client goes directly to the Internet to retrieve email. All four PC use the same ISP for email.
The fourth client PC was unable to retrieve email like the others until I added two rules to the ISA firewall. One rule to allow POP and one rule to allow SMTP.
Why could the fourth PC client not pass through the firewall while the other three could? I even added the email account from the fourth PC user on one of the other PC’s and we were able to retrieve and send email before the ISA rules were added.
We are using the ISA client on all four PC but I noticed if I disable the ISA client the user can still surf the Internet. What is the purpose for the ISA client?
Any insight would be appreciated.