You may get the following error message "’421 Cannot connect to SMTP server" in outlook and outlook express. Here I will post some of my opinions of this problem.
"An unknown error has occurred. Account: ‘Hotmail’, Server: ‘smpt.live.com’, Protocol: SMTP, Server Response: ’421 Cannot connect to SMTP server 22.214.171.124 (126.96.36.199:25), connect error 10060′, Port: 25, Secure(SSL): Yes, Server Error: 421, Error Number: 0x800CCC67"
My opinions on fixing this problem
Please check your computer and make sure that the factors listed below are not affecting your ability to send messages. You may also contact your Internet Service Provider and verify if they are blocking Port 25.
a. You may be using the Incorrect SMTP settings.
b. Your firewall software is blocking your e-mail client or the port for outgoing messages (Port 25) is being blocked by your security software.
c. Your router has a firmware setting to block certain communication ports (specifically port 25).
d. Your ISP has blocked access to port 25.
I also suggest using port 587 instead of port 25. This will help you to get around any blocks set up on port 25.