Keywords: WordPress + NGINX + SSL - Google Cloud Platform - Technical issue - Email configuration (SMTP)
I just fresh install wordpress+nginx+ssl.
Check email, contact form 7, test email, mailgun test are all working.
However, my theme email is not working. When new user try to register on my site, they never receive their verification email.
Then the theme author return to me:
"We have investigate it in details and find out that your server is not sending email when there is any text/html in email header. You server is only sending email with standard text/plain header only."
Reply from Mail Gun on who is responsible to be adjusted:
"Whichever one explicitly creates the MIME is the one that will need to be adjusted. Wordpress has WPMail as the main mail program while there are likely other extensions that can create the MIME as well. If it is PHP that is creating the emails, the change will need to occur in an application like PHP Mailer or SendMail or another type of application like the Laravel SMTP framework."
I am using Mailgun plugin and your suggested WP smtp plugin results the same problem
What should I do?