First, make sure you have checked in the account properties of the Outlook Express / MS Outlook the option “My server requires authentication”. Please note that if you are using a different email client the settings might be different.
If not, proceed to the following test. Open Command Prompt (Windows -> Start menu -> Run -> type “cmd”) and type:
For clients with premium hosting accounts:
telnet mboxhosting.com 25
For free hosting clients:
telnet free.mboxhosting.com 25
Press “Enter”
If you do not get a response 220 mboxhosting.com mail server or 220 free.mboxhosting.com mail server this means your PC (Firewall or Antivirus Program) blocks port 25 and thus filters your outgoing emails.
Solution: Disable the option of your/your network firewall to block port 25, contact the system administrator, ISP, or Antivirus Program producer for help on how to disable port 25 filterings. Alternatively, you may use port 587.
