I’ve been using the following to test that html email templates come through formatted correctly in different clients:
curl --ssl-reqd --url 'smtps://smtp.gmail.com:465' --user '{EMAIL}@gmail.com:{PASSWORD}' --mail-from '{EMAIL}@gmail.com' --mail-rcpt '{EMAIL}@gmail.com' --upload-file {FILE}
And all of a sudden I’m getting "curl: (67) Login denied" – the login details are definitely correct and nothing’s changed on my end. My guess is that google is now blocking non SSO email logins?
>Solution :
Don’t know if will solve your problem, but if you have enabled 2-Step Verification in your Google account, you have to create some app password