hello my friend , i have faced this problem before and i will explain how to solve it. first thing that u have to konw http or proxy doesn't support outlook application so u must use firewall client in order to use outlook .
stpes.
1- install firwallclient in every PC.
2- configure ISA to allow outlook traffic ------- open ISA --select configureation ---- General --- Define Firewall client Setting -- Application Seting -- "" you will see list of application" -- select Outlook--- key = Disable ---- Value = change it to 0 then Okay.
3- set firewall rule in order to send and receive mails ----- name it Outlook Traffic -- include " pop .. pop3..smtp .. smtps " but in the same time make new port protocal -- name it Outlook port --- make it TCP protocal --- Direction Outgoing -- From 587 To 587 okay and includ it with pop .pop3.smtp.smtps. Outlook port.. now every thing is okay.
4- in outlook configuration make outgoing Smtp Server 587 instad of 465 and type of encrypted connection Auto.
now u can send and receive normally and there's no any problem
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Good Luck
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