What Is SMTP Authentication and How Do I Turn It On?

SMTP authentication means logging in to the outgoing server with your username and password when sending email. If it is off, your emails are not sent and you usually see a 550 Relaying denied error.

In short
  • Authentication must be on for the outgoing server (SMTP).
  • The username is your full email address and the password is your email password.
  • Use the same details as for the incoming server.

Turning it on in Outlook

  1. Open File > Account Settings > Account Settings.
  2. Select your email account, click Change, then More Settings.
  3. On the Outgoing Server tab, tick My outgoing server (SMTP) requires authentication.
  4. Choose Use same settings as my incoming mail server and save.

In the new Outlook this setting is under Settings > Accounts > Email accounts > Manage; when you add the account as IMAP, authentication is on by default.

Turning it on in Thunderbird

  1. Go to Account Settings > Outgoing Server (SMTP).
  2. Select your server and click Edit.
  3. Authentication method should be Normal password and User Name your full email address.

On phones

On iPhone and Android, don't leave the username and password fields empty in the outgoing server settings. Step-by-step guides: Android · iPhone

Need help? Open a support ticket from your client area or call +90 216 348 35 03.
  • 34 Users Found This Useful
  • sunucu kimlik doğrulması
Was this answer helpful?

Related Articles

Where Do I Check My SMTP Settings?

If you can't send email, first check the outgoing server (SMTP) settings in your email program....

What Are IMAP and POP3, and Which Should I Choose?

IMAP and POP3 are the two ways your email program fetches incoming mail from the server. If you...

Outlook Data Files: What Are PST and OST?

Outlook stores your email, contacts and calendar in data files on your computer. There are two...

How Do I Back Up My Outlook PST File?

Backing up the PST file is the easiest way to protect your Outlook email, contacts and calendar....

What Is Horde Webmail?

Horde is a Webmail interface that offers calendar, task and note features alongside email. It is...