Authentication unsuccessful, the request did not meet the criteria to be authenticated successfully. Receiving the mentioned issue while configuring Office365 SMTP.

Question

I tried it with username, password-based authentication, and access token authentication. For which I'm receiving "535 5.7.139 Authentication unsuccessful, the request did not meet the criteria to be authenticated successfully. Contact your administrator. [PN3PR01CA0091.INDPRD01.PROD.OUTLOOK.COM 2023-10-25T11:19:30.768Z 08DBD3E4FB96EBF9" this error even though the username and password or the access token is valid.

Following are the SMTP settings :

address = "smtp.office365.com"

port = 587

user_name = "{username}"

password = "{password}"

authentication = "login" I also tried "plain"

enable_starttls_auto = true,

Also,

Is there a way to fix the above issue without setting the organizational level security defaults as "disabled"?

Answer 1

Hi @Prasenjit Hiwale

Is there a way to fix the above issue without setting the organizational level security defaults as "disabled"?

If you use basic authentication, it is not possible without disabling the Azure Security Defaults.

To use basic authentication for SMTP, the requirements are:

1.SMTP AUTH enabled for the mailbox

2.MFA disabled for the mailbox

3.Azure Security Defaults is set to disabled

4.No conditional access policy applied to this mailbox which blocks basic authentication

Otherwise you may need to consider using modern authentication instead.

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