Helpful guidelines



The NT LAN Manager (NTLM) Authentication: Simple Mail Transfer Protocol (SMTP) Extension specifies how an SMTP client and SMTP server can use the NTLM Authentication Protocol, as specified in [MS-NLMP], so that the SMTP server can authenticate the SMTP client.

How do I check Exchange SMTP authentication?

Using telnet to test authenticated relay in Exchange

  1. Connect to the SMTP Server. C:>telnet 25.
  2. Login to the STP Server. AUTH LOGIN. 334 VXNlcm5hbWU6.
  3. Conversation in Base64. AUTH LOGIN. 334 VXNlcm5hbWU6.
  4. Translated back to plain text. AUTH LOGIN.
  5. Send the test email. mail from:[email protected].

Is Telnet authenticated?

In order to authenticate to a remote SMTP host via telnet, Basic Authentication must be allowed in its settings. Basic Authentication is enabled by default on Exchange servers on the corporate network. This type of authentication involves sending the username and password over the network in base64 encoded form.

Does NTLM use HTTP?

NTLM over http is using HTTP persistent connection or http keep-alive. A single connection is created and then kept open for the rest of the session.

What is NTLM authentication in Outlook?

NTLM is a proprietary secure authentication protocol from Microsoft. The NTLM protocol allows Robin to connect to an external Exchange host without transmitting a user’s password.

How does SMTP AUTH work?

SMTP Authentication is the mechanism by which the clients of an ISP identify themselves to the mail server through which they intend to send email. It is not possible for any person to send email via any mail server they choose; mail servers will only allow the sending of email by legitimate users.

How do I test SMTP Authentication using telnet?

To test SMTP authentication via telnet:

  1. In a telnet client such as PuTTY, connect to the SMG appliance: telnet 587.
  2. Greet the mail server: EHLO
  3. Tell SMG you want to authenticate with it: AUTH LOGIN.
  4. Paste the base64 encoded username.
  5. Paste the base64 encoded password for the username.

How do I test SMTP Authentication in Office 365?

Technical : How to test Office 365 SMTP server using Powershell

  1. Step 1: Run Powershell.
  2. Step 2: Enter your Office 365 User Details.
  3. $msolcred = get-credential.
  4. Step 3: Send Mail.

How do I test SMTP authentication using telnet?