---
title: "Fixing the dovecot_config_version Error in Dovecot 2.4"
language: en
topics: ["linux", "server"]
full_article_url: https://willem.com/en/2025-06-04_breaking-changes/
---
# Fixing the dovecot_config_version Error in Dovecot 2.4

*Dovecot 2.4 refuses to start without dovecot_config_version — here's how to fix it.*

> After upgrading to Dovecot 2.4, the server refuses to start with "dovecot_config_version not set." This is by design — Dovecot 2.4 requires a complete configuration rewrite. Here's what you need to know.

Dovecot 2.4 introduced a mandatory `dovecot_config_version` setting. Without it, the server won't start. This isn't a bug — it's Dovecot's way of forcing you to review your entire configuration, because the syntax has changed significantly.

Add this to the top of your `dovecot.conf`:

`dovecot_config_version = 2.4.0`



But don't stop there. Simply adding the version line will get Dovecot to start, but your old 2.3 configuration likely contains deprecated settings that will cause problems. The `mail_location` setting, SSL certificates, and SQL authentication have all changed syntax.

Willem's complete migration guide covers every breaking change — from variable notation to encryption settings to the Sieve plugin.