Bulk Mac Mail is an an application for sending personalized mass email messages. It allows you to use message templates with multiple custom fields from the recipient database inside your messages. Customer lists can be imported from files of any type. Since all messages go through the standard Apple Mail's message delivery framework, they are absolutely indistinguishable from the messages that were actually sent by Apple Mail.
PbulkMailer is a bulk email application. Instead of a database, it works with CSV files and has a simple text file configuration. It sends directly to an MX, via a smarthost/relay, or through email accounts. Plain text and HTML messages are supported along with attachments. Per-email customization of subject, name, and body elements is allowed. Delivery and failure are logged to CSV files, and message reads, unsubscription, and spam reporting are handled using included PHP scripts.