Emails not delivered or ending up into the spam folder
Posterno relies on WordPress wp_mail() php function to send all emails managed by the plugin. WordPress then, relies on your host to send emails. It is possible that your host is not properly configured to handle the PHP mail() function, therefore WordPress fails to send emails.
Luckily there are many tutorials and alternative ways to send emails through WordPress. Many websites integrate third party services to send emails.
We suggest you read the following tutorial in order to understand how to fix emails on your WordPress website: