Email Setup Center
  • Home »
  • Smtp Error 550 

How To Fix Smtp Error Code 550 

If you see the SMTP error code 550 on an email client such as Microsoft Outlook and Mozilla Thunderbird, perform the troubleshooting steps given below.

  • First, check if you have entered the correct email address.
  • Try to send the email after one or two days as the server of the recipient could have been down when you had sent the email.
  • Go to the MX Lookup web page and check if the email is blacklisted.
SMTP error code 550

SMTP authentication:

If you have the Microsoft Outlook 2013 or 2016 email client, proceed with the following steps to enable SMTP Authentication.

  • On the main interface of the Microsoft Outlook 2013/2016 application, navigate to the Tools menu and click the Account Settings option.
  • Choose the email address of your account to fix the SMTP error code 550 and click the Change option.
  • After you click the More Settings option, the Internet Email Settings dialog box will appear on the screen.
  • Go to the Outgoing Server tab and select the checkbox next to the ‘My outgoing server (SMTP) requires authentication’ option.
  • Click the radio button beside the ‘Use same settings as my incoming mail server’ option and select the OK option.

If you are using the Mozilla Thunderbird email client, carry out the easy steps.

  • On the main window of the Mozilla Thunderbird email client, click the Tools tab and select the Account Settings option.
  • Select the Outgoing Server option on the left panel, choose an email server, and click the Edit option.
  • Go to the Settings section and check if the Server Name and Port fields are entered correctly.
  • Navigate to the Security and Authentication section, select the checkbox beside the Use secure authentication option, and click the OK option.
  • Check if the SMTP error 550 problem has been resolved.
  • If required, contact our technical experts by clicking the Call button available on this page to fix the SMTP error code 550.