I can’t understand with sending of the order to the buyer and the seller. When ordering, it is written that everything is fine, the order is issued, but the letter never comes. The mail settings are used by default, and if you use their settings, it is generally not sent and displayed error. Say please, how to configure e-mail?
You probably screwed up the smtp options, you could just use the simple php mailer or the host might have put some limitation on your server (free hosting?)
Hosting free, in the mail settings, nothing changed. In the plugin settings I tried in different ways, with the default settings and specify the server settings for SMTP.
Uploaded to another server, also with a free tariff, on it also letters with the order are sent, but do not come to the addressee (the buyer).