activeMailLib: Validate addresses and send email with attachments

activeMailLib is a class that can validate e-mail addresses and send MIME email messages using the PHP mail() function.

It can generate text or HTML E-mail messages with user defined headers, body parts and character encoding.

File parts can also be attached to the messages.

The class may also perform email address validation based on a regular expression. It may optionally check the addresses with the destination SMTP server using PHP getmxrr() function on Unix-like systems.