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Troubleshoot Email not working

This short article has items to review when troubleshooting Microsoft SMTP Servers.  If you have more tips / tricks.  Feel free to email us as info@smtp.ws and we'll add to the list.

  • Have you run SMTP Diag?
  • Does the server sending mail have a static IP address?
  • Does the mail server have internet connectivity?
  • Does the account sending messages have permissions on the PICKUP folder (usually c:\inetpub\mailroot\pickup)
  • Does your ISP allow port 25 connectivity?
  • Does your mail server has a reverse or PTR dns record?
  • Have you enabled logging and reviewed messages when sending to an external account such as gmail.com, hotmail.com, yahoo.com?
  • Can you ping external dns servers?
  • If you run an external mail server, is your mail server on a RBL list (www.spamhaus.org for example).  DNSStuff.com has a great tool that checks several.
  • Do you have anti-virus software locally on the server blocking port 25?
  • Try Telnet to the receiving SMTP server on port 25 and see if there is connectivity (telnet mail.example.com 25)
  • Try pinging the receiving mail server and see if it responds.