SMTP - AUTH not accepted from server: 504 5.7.4 Unrecognized authentication type

Question

I have two servers connected via vpn. Got sending emails through an SMTP server on another server. My server runs CentOS. I am using phpmailer (in php: P), and on the other hand we have Microsoft Exchange 2010 Server.

An IT server running on an MS Exchange server created a VPN and loggon from its location and authenticated NTLM correctly.

The situation is as follows:

• It can connect without problems.
• Can send anonymous letters without any problems.
• It is not possible to authenticate through NTLM no matter what.

The error is always the same; I tried hundreds, if not thousands, of combinations before giving up. MS-E does not seem to recognize auth type transfers.

Server response when trying to send mail:

250-SIZE 31457280 250-PIPELINING 250-DSN 250-ENHANCEDSTATUSCODES 250-STARTTLS 250-X-ANONYMOUSTLS 250-AUTH NTLM 250-X-EXPS GSSAPI NTLM 250-8BITMIME 250-BINARYMIME 250-CHUNKING 250-XEXCH50 250-XRDST 250 XSHADOW <br />SMTP -> FROM SERVER:220 2.0.0 SMTP server ready <br />SMTP -> FROM SERVER: 250-APOLO.xxxxxx.local Hello [xxx.xxx.xxx.xxx] 250-SIZE 31457280 250-PIPELINING 250-DSN 250-ENHANCEDSTATUSCODES 250-AUTH NTLM 250-X-EXPS GSSAPI NTLM 250-8BITMIME 250-BINARYMIME 250-CHUNKING 250-XEXCH50 250-XRDST 250 XSHADOW 

With SMTP-Debug ON, the answer is:

 <br />SMTP -> ERROR: AUTH not accepted from server: 504 5.7.4 Unrecognized authentication type <br />SMTP -> FROM SERVER:250 2.0.0 Resetting <br />SMTP Connect() failed. 2012-09-18 11:48:46 >> Error de envío: SMTP Connect() failed. 

Confirmation was received from them (IT guys) that they expect NTLM as auth type.

This is the configuration I'm sending (phpmailer's):

 PHPMailer Object ( [From] => [e-mail] [FromName] => Entorno Virtual de Aprendizaje de asdasd [Sender] => [e-mail] [ReturnPath] => [Mailer] => smtp [UseSendmailOptions] => 1 [Hostname] => apolo.asdasd.local [Host] => apolo.asdasd.local [Port] => 25 [Helo] => [SMTPSecure] => tried all three of them (ssl, tls and "") [SMTPAuth] => 1 [Username] => [e-mail] [Password] => xxx_2012 [AuthType] => NTLM [Realm] => [Workstation] => [SMTPDebug] => 2 [Debugoutput] => echo [SMTPKeepAlive] => [smtp:protected] => [language:protected] => Array ( [authenticate] => SMTP Error: Could not authenticate. [connect_host] => SMTP Error: Could not connect to SMTP host. [data_not_accepted] => SMTP Error: Data not accepted. [empty_message] => Message body empty [encoding] => Unknown encoding: [execute] => Could not execute: [file_access] => Could not access file: [file_open] => File Error: Could not open file: [from_failed] => The following From address failed: [instantiate] => Could not instantiate mail function. [invalid_address] => Invalid address [mailer_not_supported] => mailer is not supported. [provide_address] => You must provide at least one recipient email address. [recipients_failed] => SMTP Error: The following recipients failed: [signing] => Signing Error: [smtp_connect_failed] => SMTP Connect() failed. [smtp_error] => SMTP server error: [variable_set] => Cannot set or reset variable: ) 

I need a hand or at least a hint, I hope that this information will be enough.

Answer 1

Apparently, the server considers NTLM to be something different from your SMTP client (PHPMAILER). Check if it is REALM, which is empty for you, and may be required (by default) with SMTP during exchange. The problem, perhaps, can be solved in either of the two sides, however, while you are the one who connects and requests, this is their server, which does not accept anything. You should ask them about some logs or a detailed error message; they should have errors in their exchange event viewer. I would also check with someone else's NTLM client, just to make sure that it is POSSIBLE to authenticate correctly from your computer (to find out if this problem is general authentication or if the PHPMAILER authentication problem is confirmed).