Module ngx_mail_pop3_module

• Directives
• pop3_auth
• pop3_capabilities

Directives

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

plain

USER/PASS, AUTH PLAIN, AUTH LOGIN. It is not possible to disable these methods.

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 (1.11.6).

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 nginx transparently proxies the client connection to the backend).

The current list of standardized extensions is published at www.iana.org.