Hello Aki,
Thank you for the pointer to https://repo.dovecot.org. I have now installed Dovecot 2.4.4 from the official repository on Ubuntu 24.04 LTS (Noble) and can confirm that the packages are available and install correctly. However, checking the build options shows that PCRE support is not included:
$ dovecot --build-options Build options: ioloop=epoll notify=inotify experimental-imap4rev2 openssl io_block_size=8192 SQL driver plugins: mysql postgresql sqlite Passdb: ldap pam passwd passwd-file sql Userdb: ldap(plugin) passwd prefetch passwd-file sql
There is no PCRE entry, and sieve-test still rejects all (?i) inline flags in regex expressions with "invalid preceding regular expression". May I ask: is PCRE support intentionally not included in the official Dovecot/Pigeonhole packages, or is this an oversight in the build configuration? If PCRE is not planned to be included, is there a recommended alternative approach for achieving case-insensitive regex matching in Pigeonhole's sieve-test that would be compatible with Cyrus IMAPd's PCRE-based regex syntax?
Thank you again for your help. Best regards, Michael Merz michael.merz@wtnet.de
-----Ursprüngliche Nachricht----- Von: Aki Tuomi via dovecot <dovecot@dovecot.org> Gesendet: Freitag, 10. Juli 2026 06:51 An: Michael Merz <michael.merz@wtnet.de>; Michael Merz via dovecot <dovecot@dovecot.org>; Stephan Bosch <stephan@rename-it.nl> Betreff: Re: sieve-test (Pigeonhole) on Ubuntu: PCRE support and address test restrictions on Return-Path
You can get 2.4.4 packages for ubuntu 24.04 from https://repo.dovecot.org
Aki
On 09/07/2026 22:21 EEST Michael Merz via dovecot <dovecot@dovecot.org> wrote:
Dear Stephan,
Thank you very much for your quick and helpful response.
Regarding point 1 (PCRE support), your comment that Ubuntu 24.04 is "likely stuck at a quite old version of Pigeonhole" raises a follow-up question:
From which version of Pigeonhole onwards is PCRE support included by default (i.e. compiled in without requiring an explicit --with-pcre flag)? And is there an official repository, PPA, or recommended way to obtain a more recent Pigeonhole/dovecot-sieve binary for Ubuntu 24.04 LTS that would include PCRE support out of the box?
Regarding point 2 (Return-Path / envelope test): thank you for the pointer. I understand that the envelope test would be the RFC-compliant alternative within Pigeonhole. However, since my ruleset runs on a Cyrus backend where the address test on Return-Path works fine, this would mean maintaining two different versions of the ruleset — one for production (Cyrus) and one for offline testing (Pigeonhole). That somewhat defeats the purpose of offline testing, so I mention it only for completeness.
The key question therefore remains whether a PCRE-enabled Pigeonhole binary is realistically obtainable for Ubuntu 24.04, as that would resolve the main blocker.
Thank you again for your time.
Best regards, Michael Merz
von meinem iPad Pro 4Gen gesendet
Am 09.07.2026 um 18:39 schrieb Stephan Bosch <stephan@rename-it.nl>:
Op 29-6-2026 om 09:56 schreef michael.merz--- via dovecot:
Hello,
I've been evaluating sieve-test (Pigeonhole, dovecot-sieve package, version 2.3.21, as shipped with Ubuntu 24.04 LTS) as an offline testing tool for a personal Sieve ruleset that currently runs on a Cyrus IMAPd/CMU Sieve 3.0 backend.
Different implementation and design choices will mean that Dovecot has a different opinion what is a valid Sieve script and how it is to be evaluated than Cyrus, making this problematic.
I'd like to ask for some clarification on two points, in case I'm missing a configuration option.
- PCRE support
My ruleset makes extensive use of the
(?i)inline case-insensitivity flag within :regex tests, which is valid under PCRE (as used by Cyrus).When running sieve-test, I get:
error: invalid regular expression '(?i)...' for regex match: invalid preceding regular expression.Checking
dovecot --build-optionsshows no PCRE entry, which suggests the Ubuntu-packaged binary was compiled without --with-pcre and falls back to POSIX extended regex.Question: Is PCRE support in Pigeonhole's regex extension purely a compile-time decision (i.e. something that would need to be addressed at the distribution packaging level, not via runtime configuration), or is there a runtime way to enable PCRE matching that I might have missed (e.g. via -o, sieve_extensions, or similar)?
It is strictly compile-time configured. I didn't implement the PCRE migration myself, but I don't think there is a POSIX regex fallback for it. This likely means your Ubuntu version is still stuck at a quite old version of Pigeonhole.
- Return-Path in the
addresstestSeveral of my rules use:
address :domain :is "return-path" "..."Cyrus accepts this. Pigeonhole's sieve-test rejects it with:
error: specified header 'return-path' is not allowed for the address test.I understand this is likely an RFC 5228 strictness difference (Cyrus being more permissive than the RFC requires).
Is there a recommended alternative within Sieve itself to achieve the same effect (testing the address portion of Return-Path) while staying within what Pigeonhole accepts -- e.g. via the
headertest combined with some address-parsing approach, or via the envelope test instead?Envelope test is best if you want to use address matching.
For context: I'm not running a Dovecot mail server myself.
I'm using sieve-test purely as an offline syntax/behaviour verification tool before deploying ruleset changes to a separate Cyrus-based production system.
I understand this is a bit of an unusual use case, so any guidance on whether Pigeonhole is well suited for this kind of cross-implementation testing at all would also be appreciated.
Thank you for your time and for maintaining Pigeonhole.
Best regards,
Michael Merz
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