Email settings
Server settings » Email settings
Mail Server Settings
Mail host:
smtp.gmail.com
Email security
X Enable TLS
Google’s Gmail Outgoing Mail (SMTP) Server settings
https://support.google.com/mail/answer/7126229?hl=en&visit_id=1-636296667856054854-1257014222&rd=1
*** Look for Google blocking
Review blocked sign-in attempt
and whitelist in google if necessary and you accept the risks!
I found toggling this google setting helped achieve whitelist-like status, that and using stronger TLS helps
https://myaccount.google.com/lesssecureapps
