You can set the email signature that WHMCS adds to all outgoing email templates. This signature will automatically appear at the end of every email message that the system sends to your customers using an email template.
You can configure Google as your mail provider using SMTP. This requires creating an app in the Google Cloud console and configuring SMTP as your mail provider.
You can configure Microsoft® as your mail provider using Microsoft Entra® ID (formerly Azure Active Directory). To do this, you will also need to create an app in the Microsoft Entra console.
You can configure SparkPost, SendGrid, or Mailgun as your mail provider.
You can configure SMTP as your mail provider. Make sure to choose the mail provider that offers the best service and security features for you.