Can not send email using Outlook (Server Error: '550')

If you are receiving an error similar to this when sending email using Outlook:

"The message could not be sent because one of the recipients was rejected by the server. Server Response: '550 not local host, not a gateway', Port: 25, Secure (SSL): No, Server Error: 550, Error Number: 0x800CCC79

  1. Open your Outlook settings (Tools ->Accounts)
  2. Go to View/Change email account for the email account you are having problems with.
  3. Check that the SMTP Server is set to mail.yourdomain.com
  4. Go into the "More settings", "Outgoing Server" tab and make sure that the option "My server requires authentication" for the Outgoing server is checked ON.
  5. Save and close all windows.
  6. Try again.

If the problem continues then the problem is that your Internet Service Provider is blocking port 25 on the outgoing mail server. ISPs do this to prevent spam on their network. When this happens you will need to use the mail server that they provide you instead of your own. The mail server is generally smtp.yourISPname.com, however, it could be different so please contact your ISP to get the details.

If you do not want to use your ISPs server for SMTP, and the ISP is blocking port 25, you can switch the port to 587 for your outgoing mail and use mail.yourdomain.com for the SMTP server name.

  • 0 Users Found This Useful
Was this answer helpful?

Related Articles

Adding FTP Accounts

Adding FTP Accounts If you are working on your website together with someone else or host...

Create an Email Accounts

Adding Mail Accounts To create an e-mail address: If you are subscribed to several hosting...

Configure POP for iPhone, iPad or iPod Touch

With POP3, your mail is saved in a mailbox on the remote server until you check your mail....

creating-or-removing-scheduled-tasks-in-plesk

Creating or Removing Scheduled Tasks in Plesk  On Windows servers, you can set them up to...

Creating Databases

Creating Databases To create a new database on a hosting account: If you are subscribed to...