POP3#

Adds POP3 support to the mail proxy: Angie handles a POP3 client itself until the authentication server accepts the client, then relays the session to a backend. Until then, Angie answers CAPA, receives the client's credentials by one of the methods listed under pop3_auth, and rejects mailbox commands such as LIST or RETR (see How It Works).

When building from the source code, the module is built by default together with the Mail module (enabled with --with-mail); it can be disabled with the build option --without-mail_pop3_module.

In packages and images from our repositories, the module is included in the build.

Directives#

pop3_auth#

Syntax

pop3_auth method ...;

Default

pop3_auth plain;

Context

mail, server

Sets permitted methods of authentication for POP3 clients. Supported methods are:

plain

USER/PASS, AUTH PLAIN, AUTH LOGIN

apop

APOP. In order for this method to work, the password must be stored unencrypted.

cram-md5

AUTH=CRAM-MD5. In order for this method to work, the password must be stored unencrypted.

external

AUTH=EXTERNAL

xoauth2

AUTH=XOAUTH2

oauthbearer

AUTH=OAUTHBEARER

Plain text authentication methods (USER/PASS, AUTH PLAIN and AUTH LOGIN) are always enabled, though if the plain method is not specified, AUTH PLAIN and AUTH LOGIN will not be automatically included in pop3_capabilities.

pop3_capabilities#

Syntax

pop3_capabilities extension ...;

Default

pop3_capabilities TOP USER UIDL;

Context

mail, server

Sets the POP3 protocol extensions list that is passed to the client in response to the CAPA command. The authentication methods specified in the pop3_auth directive (SASL extension) and STLS are automatically added to this list depending on the starttls directive value.

It makes sense to specify the extensions supported by the POP3 backends to which the clients are proxied (if these extensions are related to commands used after the authentication, when Angie transparently proxies the client connection to the backend).