SMTP Error: Could not authenticate..!

Hi,

I have been trying to use the WP Mail Smtp Mailer plugin (to avoid sending things via GoDaddy host servers) and I get this message:SMTP Error: Could not authenticate..! When I try to send a test message. I am trying to use it with a gmail account. I have tried it with both of these:
? Gmail :- Host: smtp.gmail.com – Secure(SSL) – Port(465)
? Gmail :- Host: smtp.gmail.com – Secure(TLS) – Port(587)
I can’t figure out what I am doing wrong. Thanks in advance for your help. Mail Poet 2, WP-SpamShield and Caldera forms are also installed. Plugins and WordPress are up to date.

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