Error: :javax.mail.AuthenticationFailedException: AUTHENTICATE failed

[Hfhex 4]

Hello everyone. I hope you are well. I would like to ask for your kind collaboration with the following:

-I am automating a scenario of sending an email through SMTP in Jmeter version 5.6.3 and I need to validate its content (validate that the text or labels of the message are centered).

 I have tried to verify the reception and content of the email with a Mail Render Sampler and using the JavaMail library version 1.6.2 but the following error message is appearing:
Response message:javax.mail.AuthenticationFailedException: AUTHENTICATE failed

I did the test with an Outlook email and with a Gmail email. With IMAP and POP3, but the same thing happens. I have been investigating the error and they tell me that it is due to an issue of activating a password for the applications (provide a simple password, create an application password), but when validating I cannot find this option in Gmail and in Outlook I found it, the I generated it but it didn't work for me.

--->  Office 365 Go to MYAccount-->Security & Privacy-->Additional Security Check-->Create and Manage App Passwords

--_> Gmail: Activate 2-Step Verification Google Account and create the password.

I don't know if the error is due to the configuration of the application password, if it is due to the javamail version, or if it is due to the IMAP or POP configuration in the Mail Render Sampler, which I mention at this moment:

1.IMAP configuration:
Protocol: imaps
Server Host: outlook.office365.com
Port:993
User: xx...@outlook.com
Password: XXXXX
Folder; INBOX
Security settings; Use SSL or Use StartTLS
===============================================================
2.POP3 configuration:
Protocol: pop3
Server Host: outlook.office365.com or pop.gmail.com
Port:995
User: xx...@gmail.com
Password: XXXXX
Folder: INBOX
Security settings; Use SSL or Use StartTLS

On the other hand, I don't know if there is another element of Jmeter or another library that allows me to validate the content of the email.

I appreciate your advice, your comments and help.