PowerMTA SMTP server is a software application which allows users to send large amounts of e-mails. It is often used by companies who have to send a lot of emails on a regular basis, such as newsletters or promotional material or trnsactional mails. PowerMTA can be configured to send email using various protocols such as SMTP, HTTP and SMPP. It also offers many features that are great for bulk emails, such as support for multiple DomainKeys/DKIM signatures and the ability to throttle email delivery to avoid overloading recipient mailboxes. Additionally, PowerMTA provides detailed logs that can be used to troubleshoot any issues that may occur during the email sending process.