Install guide · Debian 13 (trixie)printed 29 Oct 2026, 02:20 UTC

Install PostSRSd 2.4 on Debian 13

Debian 13 ships PostSRSd 1.10. The current release is 2.4.1. freshdeb builds it for trixie from upstream's release with Debian's packaging, so it replaces the distribution's package in place and updates with apt upgrade like the rest of the system. trixie-backports has 2.4.1, which apt only installs when asked to.

Debian 13 ships: 1.101.10-2.2
main: 2.4.1follows every upstream release, minors and majors included. Currently 2.4.1.
Built for: amd64 and arm64, natively

1Trust the signing key (once per machine)

sudo install -d -m 0755 /etc/apt/keyrings
curl -fsSL https://deb.freshdeb.com/freshdeb-archive-keyring.gpg \
  | sudo tee /etc/apt/keyrings/freshdeb-archive-keyring.gpg >/dev/null

Fingerprint 3BBD F03A 9C0B F890 F8CA 9510 7595 CC55 468F 3161. How to verify.

2Add the source for trixie

sudo tee /etc/apt/sources.list.d/freshdeb-postsrsd.sources >/dev/null <<EOF
Types: deb
URIs: https://deb.freshdeb.com/postsrsd
Suites: trixie
Components: main
Signed-By: /etc/apt/keyrings/freshdeb-archive-keyring.gpg
EOF

3Install

sudo apt update && sudo apt install postsrsd
apt policy postsrsd   # expect 2.4.1-2+freshdeb~deb13

Already on Debian 13's PostSRSd? The same command upgrades it: the freshdeb version sorts higher. What's different from Debian's package.

Upgrading from PostSRSd 1.10

What changed between Debian 13's 1.10 and 2.4.1 that you may notice. Configuration and data stay where Debian put them.

Since 2.0: PostSRSd 2 reads /etc/postsrsd.conf instead of /etc/default/postsrsd. The upgrade carries your settings over (domains, secret, separator, hash lengths, user, chroot) and keeps the secret, so addresses 1.x rewrote still reverse. Postfix needs a change the package can't make: 2.x answers socketmap: lookups on /var/spool/postfix/srs instead of tcp: tables on ports 10001 and 10002. In /etc/postfix/main.cf, set sender_canonical_maps = socketmap:unix:srs:forward and recipient_canonical_maps = socketmap:unix:srs:reverse, keep the classes, and reload Postfix. Until then Postfix defers mail and retries it later.
Debian 13: trixie-backports has PostSRSd 2.4.1 as well. This repository follows every upstream release, and carries the 1.x settings over, where Debian's package only documents the migration.

Going back to 1.10

Delete /etc/apt/sources.list.d/freshdeb-postsrsd.sources, run sudo apt update, then sudo apt install postsrsd=1.10-2.2: apt asks before it downgrades. PostSRSd 1.x reads /etc/default/postsrsd again, which the upgrade leaves in place, and Postfix needs its tcp: lines back.

Why a package

The upstream source builds with CMake, but then the service, the user, the chroot and the AppArmor profile are yours to set up. This is Debian's package, with all of that, at upstream's current release.

PostSRSd elsewhere

postsrsd: every release line, its contents and origin