Hi there @larrybohen,
Our plugin bridges a connection between your WordPress site and your mailer service. This connection makes it so emails sent by your WordPress site are funneled over and delivered by your mailer service. For instance, if you connect WP Mail SMTP to SendLayer, emails from your site will be sent by SendLayer instead of your web host’s server. This improves the reliability and efficiency of your email to make sure your email lands in inboxes instead of spam folders or being rejected by the server.
Regarding the sending domain and From address, unless you’re connecting to the site’s SMTP server, you’ll be sending from the mailer service you connect to. When it comes to the From address, mailer services have their own requirements. Most want you to send From an address using the domain you register under their service. So for instance, if you register example.com under the mailer service account, you would need to send emails From any @example.com address. Brevo is a bit more flexible in that you can use any From address with it.
Check out this guide in our documentation. It walks through each mailer we support and includes the benefits of each: https://wpmailsmtp.com/docs/a-complete-guide-to-wp-mail-smtp-mailers/
I hope that helps! Have a great day! ??
