i cant send emails to some gmail accounts from TPGI

[garinda]

i am getting an error message when trying to send emails to some gmail accounts.  550-5.7.26 this mail has been blocked because the sender is unauthenticated.  it doesnt happen with all gmail accounts but is becoming more frequent.  Some previously sent gmail emails are now bouncing back with same message.  

[david64]

Hi @garinda . Is this happening with Post Office or email client?

If client, is it only on one device (eg. computer), or on multiple devices?

[garinda]

thanks David.  it is occuring through Post Office.

[david64]

@garinda . Send an email to postmaster@tpg.com.au about the issue.

Include 3 examples of failed emails, date and time when sent and subject. And date and time when you received the error code. Include one email that did work for comparison.