ISA Server and Outlook

ISA Server and Outlook
Hi everyone,
last week i installed and configure ISA Server on our network in integrated mode.Clients can now browse internet using Web Proxy on ISA Server.But problem is how can i configured outlook to use ISA Server.Our mail server is provided by our ISP,we dont have local mail server.(Our mail servers is let say, pop.mydomain.com and smtp.mydomain.com)

I already configure Packet filter to open POP3 110 incoming and SMTP 25 outgoing.How can i setup or configure my mail client to use this?

I prove whith Lotus Notes and Outlook Express and work Exelent
Thanks and hope for a response…