Email rejected

Level 2

I am unable to send an email to  .  My family members can send emails to this email via gmail but when I send from my tpg account I get the following error message.   Any advice?


The original message was received at Thu, 14 Jan 2021 15:44:43 +1100 from []


This message was generated by


   ----- The following addresses had permanent fatal errors ----- <>

    (reason: 550-Please turn on SMTP Authentication in your mail client.


   ----- Transcript of session follows ----- ... while talking to

>>> DATA

<<< 550-Please turn on SMTP Authentication in your mail client. <<< 550-[]:32880 is not permitted to relay through this server without <<< 550 authentication.

550 5.1.1 <>... User unknown <<< 503-All RCPT commands were rejected with this error:

<<< 503-Please turn on SMTP Authentication in your mail client. <<< 503-[]:32880 is not permitted to relay through this server without <<< 503-authentication.

<<< 503 Valid RCPT command must precede DATA



Hi @gvhcox


Based on the errors, it appears that you will need to turn on the SMTP Authentication on your mail client. 

  • Have you tried sending to this email address via TPG Post Office? 
  • What's the email client you are using

We'll wait for your response. 




Level 2

Dear Ahra_G


Thank you for your reply.   I am new to this forum so its taking me a while to work out how to contact you!  I have just tried sending from TPG Post Office and a pop-up box says message was successfully delivered.  And its been about 5 minutes since I sent it and have not had a returned email saying it was unsuccessful.   So perhaps it is something in my mail client.


COuld you advise what you mean by 'turn on the SMTP Authentication on my mail client'.  Is it in settings?  Settings in microsoft outlook or settings on my phone, computer, etc?


I'm also not sure what 'the email client I am using' means.  I use TPG.  On Microsoft Outlook.  And was sending to an email with the following details




Hi @gvhcox


Glad to know that you were able to send an email using TPG Post Office. That said, it means that the email server has no issues. 


You can find the 'SMTP Authentication' option under the advanced settings of your Outlook mail. 


Here's an article to guide you with the basic set up: Setting Up TPG Email for Microsoft Outlook


Let us now how it goes. 




Level 2

Hi Ahra_G


STMP authentication is ON.  There are three options available (same settings at incoming mail server; log on using username and password; and logon to incoming mail server before sending mail).  Option two (logon using username and password) is selected).  




Hi @gvhcox,



Kindly try the steps below:


Incoming mail server:

Incoming Port: 110

Make sure that both “This server requires encrypted connection (SSL/TLS) and

Require logon using secure password authentication (SPA)” are both not tick.


Outgoing mail server:

Outgoing Port: 25

Make sure that “Require logon using secure password authentication (SPA)” is not tick.


Once done, click “Next” to continue.

Let me know how it goes.