| Name | Description | Type | Package | Framework |
| AuthenticatingSMTPClient | An SMTP Client class with authentication support (RFC4954). | Class | org.apache.commons.net.smtp | Apache Commons |
| AuthenticatingSMTPClient .AUTH_METHOD | The enumeration of currently-supported authentication methods. | Class | org.apache.commons.net.smtp.AuthenticatingSMTPClient | Apache Commons |
| RelayPath | A class used to represent forward and reverse relay paths. | Class | org.apache.commons.net.smtp | Apache Commons |
| SimpleSMTPHeader | This class is used to construct a bare minimum acceptable header for an email message. | Class | org.apache.commons.net.smtp | Apache Commons |
| SMTP | SMTP provides the basic the functionality necessary to implement your own SMTP client. | Class | org.apache.commons.net.smtp | Apache Commons |
| SMTPClient | SMTPClient encapsulates all the functionality necessary to send files through an SMTP server. | Class | org.apache.commons.net.smtp | Apache Commons |
| SMTPCommand | SMTPCommand stores a set of constants for SMTP command codes. | Class | org.apache.commons.net.smtp | Apache Commons |
| SMTPConnectionClosedException | SMTPConnectionClosedException is used to indicate the premature or unexpected closing of an SMTP connection resulting from a | Class | org.apache.commons.net.smtp | Apache Commons |
| SMTPReply | SMTPReply stores a set of constants for SMTP reply codes. | Class | org.apache.commons.net.smtp | Apache Commons |
| SMTPSClient | SMTP over SSL processing. | Class | org.apache.commons.net.smtp | Apache Commons |