If they have decided to enforce AUTH for all relayed mail, it will be a challenge if you do not have the AUTH details. They probably published the information somewhere or they don't want any TDH relaying through their servers. Use your own SMTP Server sir.

On 27 November 2017 at 16:22, geoffrey gitagia via skunkworks <skunkworks@lists.my.co.ke> wrote:
Hi Guys

Anyone else affected by the below error



---------- Forwarded message ----------
From: Mail Delivery System <MAILER-DAEMON@rat01.safaricombusiness.co.ke>
Date: Mon, Nov 27, 2017 at 3:47 PM
Subject: Delivery Status Notification (Failure)
To: ggitagia@gmail.com


The following message to <XXXXX@XXXXXXXXcom> was undeliverable.
The reason for the problem:
5.1.0 - Unknown address error 550-'Please turn on SMTP Authentication in your mail client. \n(rat01.safaricombusiness.co.ke) [197.248.254.120]:42090 is not permitted to\nrelay through this server without authentication.'

Final-Recipient: rfc822;XXXXX@XXXXXXXXcom
Action: failed
Status: 5.0.0 (permanent failure)
Remote-MTA: dns; [197.248.5.12]
Diagnostic-Code: smtp; 5.1.0 - Unknown address error 550-'Please turn on SMTP Authentication in your mail client. \n(rat01.safaricombusiness.co.ke) [197.248.254.120]:42090 is not permitted to\nrelay through this server without authentication.' (delivery attempts: 0)

--
GG


_______________________________________________
skunkworks mailing list
skunkworks@lists.my.co.ke
------------
List info, subscribe/unsubscribe
http://lists.my.co.ke/cgi-bin/mailman/listinfo/skunkworks
------------

Skunkworks Rules
http://my.co.ke/phpbb/viewtopic.php?f=24&t=94
------------
Other services @ http://my.co.ke



--
Best regards,
Odhiambo WASHINGTON,
Nairobi,KE
+254 7 3200 0004/+254 7 2274 3223
"Oh, the cruft."