Answer: 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 different e-mail client the settings might be different.

If not, proceed to the following test. Open Command Prompt and type: telnet mail.yourdomain.com 25, press ‘Enter’

If you do not get response ‘220 mail.yourdomain.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 system administrator, ISP or Antivirus Program producer for help on how to disable port 25 filtering. Alternatively you may use port 587.