[solved] SMTP TLS authentication problem

[nick_developer]

Hi I'm trying Office365 SMTP, 
but I keep receiving this error message 

Failed to authenticate on SMTP. using 2 possible authenticators. Authenticator LOGIN returned Expected response code 235 but got code "535", with message "535 5.7.3 Authentication unsuccessful.Authenticator XOAUTH2 returned Expected response code 235 but got code "535", with message "535 5.7.3 Authentication unsuccessful.

I tried with other SMTP services and everything is working. 
Can be the problem be related to some authentication option in the email account ?
Is anyone getting the same error ?

 

thanks
best regards
nick

 

Edited February 24, 2021 by nick_developer (see edit history)

[7east]

following as we are having the same issue

[Adrien T]

Hello,

did you do all the steps on this :

https://docs.microsoft.com/fr-fr/exchange/mail-flow-best-practices/how-to-set-up-a-multifunction-device-or-application-to-send-email-using-microsoft-365-or-office-365

 

[7east]

Yes it turns out my host is blocking port 587

[nick_developer]

Hi I've found that the problem was about: 

- if the password is too long, or if it has some special characters in it, it returns that error
- if the sender email address ( customer support email ) differs from the user email address used in the SMTP parameters, it returns that error

best regards 
nick