OAuth with Office365 - SMTP Error

ERPNext
1

I have authorized my office email to be linked with ERPNext.
I receive emails in the communications app.

But I can not send them. Especially, when I try to save the mailbox as the default sending mailbox, I get the following error:
Please check your email login credentials. smtplib.SMTPAuthenticationError: (451, b’4.7.0 Temporary server error. Please try again later. PRX5 [PR1P264CA0152.FRAP264.PROD.OUTLOOK.COM 2024-04-24T14:10:40.106Z 08DC5FD3FB683F98]')

Not sure how to fix this, any advise?

Thank you in advance.

2

Hi,
Check the Exchange admin center whether SMTP is enabled or not.

If not kindly enable and wait for a few minutes to reflect the changes then try to set it as the default sending mailbox.

Best.

3

Hi, thank you for your quick reply.
The specific account has SMTP enabled and in the Exchange Admin the SMTP is also enableds.