5.7.8 Error: authentication failed: authentication failure

Authentication failure has nothing to do with SSL or your ports. This means your name and password combination is not permitted.

Aun?o make much sense of it .. you see my screenshot? He says that port 465 is open but not this available, how? and looks .. already changed the password to a simple “wordsimple123” nothing, password error is not. I use copypast, and the WP mail STMP I can, disabling authntication STMP on an option that your plugin has not, and I do not know because it does not, it is better not have, just know that with your plugin does not pass because using Authentication stmp can not be unmarked for us users. click on link and see you screenshot of test connection postmail.

https://www.4shared.com/download/PSkvJKOXce/erro-smtp-login-to-send.png?sbsr=adf1964a0e4397805a68adb518c0785478fa633c8fdcc12f&lgfp=3000

Only work that way:
https://www.4shared.com/download/SG_PdJTzba/only-work-that-way.png?sbsr=62e1f81b34d3c649d4ecf88bed86ebc91b402000cce8574&lgfp=3000

only works if I connect without password! without authentication login!:

https://www.4shared.com/download/cBpSXgovce/pass-ok-without-only-login.png?sbsr=04e90584ca334fe3e71ea2a184416133188bedb8ff9da741&lgfp=3000

only works if I connect without password! without authenticar login!
My biggest concern: is not unsafe leave this setting to send email without logging SMTP ?? as is possible I send mail using wordpress by this plugin without authentication?

He says that port 465 is open but not this available, how?

Since you can’t connect to localhost on port 465, then connect to localhost on port 587. Your screenshot says that it is open and supports both STARTTLS security and authentication.

My biggest concern: is not unsafe leave this setting to send email

No. The only concern is using authentication without security, then your password is sent “in the clear”.

5.7.8 Error: authentication failed: authentication failure

If you see this again, it means your username/password is not allowed on your mail server. Either the account does not exist or the password is wrong.

Yes but it is certain that the password is, and is super simple password to test, as some characters can not be accepted, changed the password to test, and I never put port 465 on my settings in the postman, I just think strange that warning NO red put on 465, saying it was not possible to connect for her, and if that would have any problems in other ports, because my settings are always
transport: SMTP
localhost
port 25 /// sometimes change to 587
NO security
autenhication: NO /// and this PASS OK

PASS OK, I get that happy design with HELLO holding a letter in one of my external emails that I use to test.
but if I use my login, that is never wrong, I use copy and paste to log in my email and never wrong login, password is correct, the user exist in my server, the email is accessed all the time between a test the other with postman I got to change my email password for a silly password to be broken(I aways very strong), as a_simple_word123 to see if the model of the password was not denied, but still always wrong password. question is not to use the security password and password are blank, have problem, because without login data being sent to that security enabled ?? because I repeat, authentication never works, you have to send emails without using Authentication by wordpress using the postman.
OFF firewall for testing,
where would that my server does not accept? It would be in the postfix server? where would that be?

Your application works without my using any password or email to any authentication, as you can see in the screenshot, use with blank sign has a problem? in blank work! I understand but work!

More a Pont: I have some sense activate STARTLS security if I disabled authntication (I was forced never works) and activated security. safety but to where? it is not security for login information? which by the way are blank!!

I have the same problem with PLAIN or LOGIN using my.mailserver.tld:587 STARTTLS

535 5.7.8 Error: authentication failed:
535 5.7.8 Error: authentication failed: UGFzc3dvcmQ6

‘UGFzc3dvcmQ6’ is the base-64 encoded version of the string ‘Password:’. When an IMAP client tries to connect to a Dovecot server using the SASL LOGIN protocol, Dovecot asks for the user’s password. If the SASL protocol attempted by the client doesn’t match the standard that Dovecot is expecting (common with spambot-compromised clients), Dovecot reports an error:

I removed underscores ( _ ) from password and the problem goes away and everything works fine.

Don’t know if it’s a sanitize problem or misconfiguration on my server