Symptom

You may have recently changed your ISP and find you’re unable to send emails via Outlook. Receiving emails is fine, only sending is affected.

  • You can receive email message but can’t send email using your Ecenica email.
  • When you try sending Outlook shows an error message similar to below:

The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was ”. Subject: ”, Account: ”, Server: ”, Protocol: SMTP, Server Response: ‘550 … Relaying Denied’, Port: 25, Secure (SSL): No, Server Error: 550, Error Number: 0x800CCC79

Cause

  • Your ISP maybe blocking access to SMTP over the default port 25. This means your Outlook is unable to connect to the SMTP server to send your email.
  • SMTP authentication may not be enabled in your email client.

Resolution