IMAP Compression

Dovecot supports the IMAP COMPRESS (RFC 4978) extension.

It allows an IMAP client to dynamically enable stream compression for an IMAP session.

Settings

Removed in version 2.4.0 (CE): Configuration of the compression level and algorithm was dropped. The extension is now enabled by default and configured with the default compression level for the available mechanism.

Removed in version 3.0.0 (Pro): Configuration of the compression level and algorithm was dropped. The extension is now enabled by default and configured with the default compression level for the available mechanism.

See imap-zlib plugin.