Problems with your system email can prevent you from sending email to clients or connecting to your mail provider.
Troubleshoot and resolve Could not instantiate mail function errors.
Troubleshoot and resolve Data Not Accepted errors.
Troubleshoot and resolve issues with valid email being flagged as spam.
The Mail tab in General Settings allows you to configure how WHMCS sends and manages email. You can choose and configure your mail provider, configure email headers and footers, and more.
You can choose from several supported mail providers for your WHMCS installation, including Google™, Mailgun, Microsoft®, PHP Mail, SendGrid, SMTP, or SparkPost.
Troubleshoot and resolve Connection unsuccessful errors with Microsoft®.