If you are unable to send mail please make sure the following steps are done:
1. Double check that your password is correct by trying to login to your account from webmail
2. Double check your settings. We provide complete tutorials for most email clients on our support portal http://support.practicalhost.com, EnsureMail section.
3. You have to make sure Authentication is enabled as per this image in Outlook or your favorite email client
4, If the above is confirmed and its still not working, try these alternate SMTP Outgoing mail ports as shown in the image below. Try one of the following ports: 587, 8025, 2525, 465
If all of the above does not work, the its obvious that your ISP or IT admin is closing all SMTP ports and your only option is to use webmail.