Upgrading Dovecot
The NEWS file, contained in the top-level of the source, contains all the important changes between releases. These changes are marked with * character.
Read them to see if there is anything that concerns you.
In general all the changes try to preserve backwards compatibility, but some changes which are meant to improve the stability and correctness of the configuration could mean breaking some existing installations. That may be a good thing, since it can expose problems which could otherwise show up as random errors.
File Formats
Since v2.4.0 release, upgrading won't silently change configuration (defaults). Either the old configuration is preserved, or startup fails asking you to upgrade the configuration file. The defaults are changed only when dovecot_config_version setting is changed.
Similarly since v2.4.0 release, upgrading won't do any backwards incompatible changes to storage files. If the release no longer supports an old storage file format, the startup fails instead. The new file formats are used only when dovecot_storage_version setting is changed.
Dovecot CE 2.3 and later
- Upgrading Dovecot CE from 2.2 to 2.3
- Upgrading Dovecot CE from 2.3 to 2.3.x
- Upgrading Dovecot CE from 2.3 to 2.4