These are some of the features: Can handle huge mailing list (live tested with 30k+ addresses). Correctly sets email headers. Sends mixed txt/html emails. (pear mail only) Remote HTML parsing. This means that Mailing Master can send a webpage with ease as well as a local file. Avoids mail server congestion with the power of Ajax. Mails are sent in chunks, a progressbar will show the advancement of the process. And more...