This documentation is for Dovecot v2.x, see wiki1 for v1.x documentation.

Forwarding parameters in IMAP/POP3/LMTP/SMTP proxying

Dovecot supports proxying various pieces of information and even variables for various protocols when forwarding connection. It requires that the sender is listed under trusted_networks. For IMAP, it uses the ID command, for other protocols, XCLIENT is used.

This feature is supported since v1.2, except for x-forward which was added in v2.2.29.

IMAP protocol

For IMAP protocol, this is done by extending the ID command. The maximum length of parameters to parse is 255 bytes. The parameters are forwarded as part of the ID command key-value list.

5 ID (x-originating-ip "" x-originating-port "143"... )

Supported parameters

POP3 protocol

For POP3 protocol, this is done with custom XCLIENT command which accepts a space separated list of key=value parameters.

Supported parameters

SMTP/LMTP protocol


None: Design/ParameterForwarding (last edited 2019-04-07 16:02:38 by AkiTuomi)