I use standart mail client on gadget (iPhone 4S and macBook) to open email,
sometime i can't send or receive mail, But when i change the port smtp 587 and pop3 955,
to smtp 25 and pop3 110, and otherwise.. problem has been solved.

May somebody know the solution & How could this be happened,
so i dont need change the port many times..!! (I have check my firewall and there is no issue), thanks