General Features:

Checking against email address
Syntax Checking Against Email Address
DNS/MX Record Checking Against Email Address
Mail Server Checking Against Email Address
SMTP (sending email)
Ability to send one or more
Ability to send HTML email
Support for SMTP server authentication
Ability to add custom headers
Ability to send bulk email
POP3 (receiving email)
Ability to communicate with POP3 server
Ability to retrieve messages from POP3 server
Ability to delete messages from POP3 server
Ability to easily store messages to disk
FTP
User can connect to any FTP server
Work with directory on server - get current directory name, change working directory, create or remove directory on FTP server
User can get file list of current working directory from FTP server
User can upload a file, download a file, rename a file or remove a file from FTP server
Provides method to disconnect from FTP server