Can send e-mails with multiple TOs, CCs, BCCs
Multipart MIME format for mail clients that do not read HTML e-mail.
Multiple ways to send e-mails (local, client, relay, command line on Unix).
Protection against mail header injection.
Embedded image support for HTML.
Address, attachment and header reset functions
Support for 8bit, base64, binary, and quoted-printable encoding.
Set charset for internationalization support
Authentication LOGIN, PLAIN, CRAM-MD5, POP Before SMTP.
SSL encryptions: TLS, SSL, SSLv2, SSLv3.
Context connection (like: socket, to use an IP address or/and port number).
Works on any platform that have installed PHP4 or greater.
Advanced trace result system for flexible debugging
Added TSL/SSL Relay support to auth() function.
Fixed an error in Bcc fields