“550 Authentication is Required for Relay” when sending email from clients

It is part of the Email Server security where all email delivery must be authenticated by the Email Software before the email is being accepted by the Email server for delivery. This is technically known as SMTP authentication.

Below, you may find the steps by steps guide indicates how to configure SMTP Authentication for email sending in respective computer software or mobile phones Outlook, Outlook Express, Eudora, Thunderbird, etc.) . This is required to avoid getting bounced back NDR/ MTP error messages such as Error 550 5.7.1 We do not relay / Error 550 No such user.

SMTP Authentication for Microsoft Outlook 2010 and above
1. Click on the “file” TAB
2. Click “Info”
3. Click on the big square button that says “Account Settings”
4. Click "Add or Remove accounts or change”
5. Select the email account from the list and click “Change”
6. The Internet E-mail Settings appear
7. Click "More Settings" Button
8. Click "Outgoing Server" TAB
9. Put a TICK next to the My outgoing server (SMTP) requires authentication
10. Choose "Use same setting as my incoming mail server"
11. Click OK
12. Click Next
13. Click Finish and you are done

SMTP Authentication for Outlook Express
1. Click the Tools menu in Outlook Express.
2.Click Accounts.
3. Highlight an email account and click Properties.
4. Click the Server tab.
5. Under the Outgoing Mail Server, check the “My server requires authentication” check box.
6. Click the Settings button.
7. Make sure that “Use same setting as my incoming mail server” is selected.
8. Click OK.
9. Click Apply.
10. Click OK.
11. Click Close.

SMTP Authentication for Mozilla Thunderbird
1. Go to Tools > Account Settings > Outgoing Server (SMTP)
2. Select the server and press the Edit… button
3. Check the Use name and password option
4. Add your username. Your username should be your full email address (e.g., “myusername@mydomain.com”)
5. Thunderbird will ask you for your password the first time you send mail and you can optionally save it at that time.

SMTP Authentication for Microsoft Entourage for MAC

1. Open Entourage.
2.Click on Tools and select Accounts
3. Select the Mail tab
4. Check your incoming and outgoing mail server.
5. Select "Option" tab (on top)
6. Choose "advanced sending options"
7. [TICK] SMTP Servers requires authentication
8. (o) Use same setting as my incoming mail server
9. Click OK
10. Click Ok (Close your account settings)

SMTP Authentication for Apple IOS based IPAD and IPHONE

1. Press HOME button
2. TAP on “Settings” icon
3. Select the Mail tab
4. TAP on “Mail, Contacts, Calendars”
5. TAP into the account to configure
6. Scroll downwards to the bottom of the Account setting
7. Under “Outgoing Server”, TAP on SMTP
8. TAP on the mail server under “Primary Server”
9. Primary Server must be “ON” while the rest is “OFF”
10. Fill in “Host Name” with your Domain’s Outgoing Server
11. Fill in “User name” with your FULL EMAIL ADDRESS
12. Fill in “Password” with your EMAIL PASSWORD
13. Use SSL must be “OFF”
14. Set “Authentication” type is Password
15. “Server Port” is 25 or 587 (Please try the alternative ports if it does not work as some country might block Port 25)
16. TAP on “Done” blue button on top corner right to confirm settings
17. TAP button on top corner left to go back to the account setting
18. TAP “Done” blue button on top corner right again to finalize account setting
19. Press HOME button to go to main screen
20. TAP on “Mail” icon and compose a test email to your own email address to test

SMTP Authentication for Apple Mac Mail Application
1. From the Mail menu choose Preferences
2. On the lower right corner of the Mailersoftware, click on Server Settings... (Under Outgoing Mail Server (SMTP)). If this option is not visible, make sure you have the correct mail account selected, and that the Accounts and Account Information tabs re selected.
3. Pull down the Authentication menu and select Password.
4. Enter your username and password.
5. Click OK.

SMTP Authentication for Email Enabled Printer/ Fax Machines
1. Login to the printer configuration screen and find the SMTP outgoing server setting page. Set the SMTP Authentication to “ON” (or ENABLE/ACTIVE) and key in the necessary email and password. Save the changes.
2. Set the POP before SMTP to ON (or ENABLE/ACTIVE). Save the changes.

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