Cannot send email - receiving 553 error (need to enable SMTP authentication)
Posted by Frank ., Last modified by Jay J on 23 February 2017 05:03 PM

If you're receiving the "553 Sorry that domain isn't allowed to be relayed through this host" error, then that means that SMTP authentication has not been enabled in your email program. You'll need to enable SMTP authentication in order to be able to send emails. Please choose your email program listed below for instructions on enabling SMTP authentication.

1) Set Up Outlook Express
2) Set Up Outlook 98/2000
3) Set Up Outlook XP
4) Set Up Netscape Mail
5) Set Up Eudora
6) Set Up Outlook Express (Mac)

Outlook Express / Outlook 98/2000

Open Outlook Express. Go to Tools --> Email Accounts to open it.

Click the Mail tab, the Mail Accounts window appears

Click the account you just created, then click the Properties button

Click the Servers tab

Check the box beside My server requires authentication, then click the Settings button

Select Use same settings as my incoming mail server and click OK

Click Apply, then OK to close the properties window. The Internet Accounts window will reappear.

Click OK to exit the Internet Accounts window, your E-mail set-up is complete.

Outlook XP

1. Launch Outlook XP

2. Select Tools -> E-mail Accounts

3. Select View or change existing e-mail accounts

4. Select the e-mail account created, and click on Change.

12. Click on More Settings

13. Click on the Outgoing Server tab

14. Check the box beside My server requires authentication

15. Select Use same settings as my incoming mail server and then click OK and you will return to the E-mail Accounts screen

16. Click Next.

17. Click Finish to exit the Internet Accounts window and your E-mail setup is complete.

Netscape Mail

Back on the Mail Servers page, enter the Outgoing Mail Server info:

    • Enter Outgoing Mail Server name;
    • Enter User name (make sure to type full email address in this field).

  1. Under the "Use Secure Socket Layer (SSL) or TLS for outgoing messages", select Always.

3. Click OK to save settings.

Now that Netscape Mail is configured, you can send and receive emails.


Right click on your new personality and click Properties from the menu that appears

Under SMTP Server, ensure the Authentication allowed is CHECKED, then click on OK

Your set-up is complete

Outlook Express (Mac)

How to configure SMTP Authentication with Outlook Express on a Mac

Outlook Express 5.02 has a bug in SMTP authentication that appears in some installations.

If you don't have Outlook Express 5.02, you will need it. Click here to download a copy, and then continue below to implement the SMTP authentication work-around.

1. Open Outlook Express and go to the menu item Tools and choose Accounts.

2. Next, select the account you need to edit (i.e., an account that requires SMTP authentication). If you have multiple accounts that require authentication, you will need to edit them one at a time.

With the account name selected (highlighted), click on Edit. This will open the dialogue box shown below.

3. On the bottom of the page, you will see Click here for advanced sending options. Click on this link/button, and the additional dialog box Advance Sending Options will open. See below.

4. Now, put a check mark in the box for SMTP server requires authentication.

Then, put a check mark in the box for Log on using. See below.

5. Now, we're getting to the Work Around part. The trick is to insert for the Account ID the username at domain_name, but instead of using the @ character, use the & character. See below.

Notice that I inserted, in the Advanced sending options box only, username&