How can I solve the "Username and Password not accepted" or "EOF" error when sending a test email via SMTP?


Error messages

SMTP email report

As a backup administrator, you may wish to use a “Custom SMTP Server” to send backup status reports. However, even after entering the correct information for the SMTP host, port, username and password, you might still run into a “Username and Password not accepted” error or an “EOF” error when clicking the “send a test email” link. Please try the troubleshooting solutions below:

EOF not accepted

Troubleshooting steps


Step 1. Check your information

First please confirm that you are using the correct username, password and SMTP port.

Step 2. Check you SMTP server settings

For the Gmail SMTP server, please try one of the solutions listed below:

Solution 1

For the sake of security and privacy, we recommend that you create an App password to grant permissions to access your Google Account.

  1. Go to your Google Account.
  2. On the left navigation panel, click Security.
  3. Under “Signing in to Google”, select 2-Step Verification and follow the on-screen steps to enable it.

    If you don’t have this option, it may be because 2-Step Verification has not been set up in your domain. In that case, please contact your domain administrator to enable it or proceed with Solution 2.

  4. Under “Signing in to Google”, select App passwords.

  5. At the bottom, click Select app and choose “Mail”, then click Select device and choose the device you’re using. Finally, click GENERATE.

  6. Copy and paste the displayed password into the CubeBackup console and send a test email to verify whether all settings are correct.

Solution 2

You can also allow less secure app access.

  1. Go to your Google Account.
  2. On the left navigation panel, click Security.
  3. In the “Less secure app access” panel, click Turn on access.
  4. Switch on “Allow less secure apps”.
  5. Now you can go back to the CubeBackup console and send a test email to verify whether all settings are correct.

Step 3. Try a different email account

If none of these tips solved the problem, it may be necessary to try a different email account, such as a Yahoo or Outlook account. If you have your own SMTP service inside your company, you may use it instead.