Sending of message failed, connection to SMTP server timed out

Hi, My problem here is about sending my emails, my email cannot be sent because of an error message that I can't connect to the SMTP server.
Send Message Error
Sending of message failed.
The message could not be sent because the connection to SMTP server smtp.sendit.nodak.edu
timed out. Try again or contact your network administrator.
As I analyzed on the error message that I pasted above, It is referring to my connection towards the SMTP server, that is why I check on my internet connection, it seems to be working because I can surf the internet, and my firewall has no restrictions regarding emails, as far as I know, I already did all the checking based on my capacity,
Please share some thoughts on what else shall I check,
Thanks guys.
