Rspamd on cPanel: what's actually supported in 2026

Every few months someone asks in the cPanel forums or on WebHostingTalk why WHM has no "Rspamd" toggle next to Apache SpamAssassin. The short answer: there isn't one, and there hasn't been one added to any cPanel & WHM release through 2026. If you're evaluating a move off SpamAssassin, this article covers what cPanel actually ships, what the unofficial integration paths look like, and where the tradeoff genuinely favours a different panel instead.

This is for operators running mail on cPanel & WHM who've read that Rspamd is faster and more accurate than SpamAssassin and want to know if — and how — they can run it on a cPanel box.

What cPanel ships instead

cPanel's inbound filtering stack is Apache SpamAssassin, invoked by Exim through the exiscan ACL at SMTP time, with scoring and disposition controlled in WHM → Service Configuration → Exim Configuration Manager. That's the entire officially supported path — no Rspamd package, no EasyApache profile, no WHM plugin from cPanel L.L.C. If you want to get more out of what's actually there, tuning SpamAssassin's thresholds and disposition covers the settings that move the needle, and cPGreyList adds a cheap pre-filter that drops single-shot botnet spam before SpamAssassin ever loads a message.

Most cPanel hosts layering on a second filtering engine reach for Imunify360's email filter instead, which does integrate natively with Exim and cPanel accounts, backed by a commercial reputation feed rather than community rule updates.

The unofficial route: Rspamd as an Exim milter

Community write-ups (search "rspamd-cpanel" on GitHub) configure Rspamd as a milter, point Exim's av_scanner/spam_scanner equivalents at it via custom exim.conf.local macros, and disable Apache SpamAssassin's hook so the two don't double-score mail. It works — people run it in production — but understand what you're taking on:

Every cPanel update to Exim's config templates is a manual re-merge. cPanel periodically regenerates exim.conf from its own templates; custom ACL blocks not registered through cPanel's supported hook system (/etc/exim.conf.localopts, exim_pre_* hooks) get clobbered on the next Exim Configuration Manager save or cpanel update.
cPanel support won't touch it. The moment Rspamd is in the mail path, any deliverability ticket you escalate gets "remove the custom integration and reproduce" as the first response.
No WHM UI. Per-account Bayes training, symbol weight tuning, and the Rspamd web UI all live outside cPanel's account model — you're managing a second admin surface by hand or via the community controller scripts.
Bayes doesn't carry over. If you're migrating an existing SpamAssassin install, its Bayes database is not compatible with Rspamd's — you retrain from scratch against a fresh ham/spam corpus, so expect a multi-week accuracy dip.

If your box handles enough volume that SpamAssassin's Perl-based scanning is genuinely CPU-bound — not just "defaults feel slow" — a milter-based Rspamd bolt-on can be worth that maintenance tax. For most shared and reseller hosting boxes, the CPU delta doesn't show up before disk I/O or PHP-FPM does.

When the answer is "switch panels, not filters"

If Rspamd is the actual requirement — not a nice-to-have — a handful of panels support it as a first-class citizen instead of a bolt-on: DirectAdmin can map SpamAssassin-style settings onto an installed Rspamd instance, and newer panels built around modern mail stacks (Enhance is the most cited one) ship Rspamd natively with a proper UI. That's a bigger decision than a mail-filter swap — see cPanel vs DirectAdmin vs aaPanel for the wider tradeoff before treating spam filtering as the deciding factor. Moving a production account base is its own project; cPanel's account transfer tooling is the mechanism if you do go that way, but panel migrations for a mail-filter preference alone rarely pencil out against just tuning what you have or adding Imunify360 on top.

Next steps

Does cPanel support Rspamd?+

No. cPanel & WHM's only built-in inbound spam filter is Apache SpamAssassin, hooked into Exim at SMTP time. There is no official Rspamd package, WHM plugin, or EasyApache profile as of 2026.

Can I install Rspamd on a cPanel server anyway?+

Yes, as an unsupported milter integration wired manually into Exim's config — community scripts exist for this. It survives outside cPanel's supported hook system, so Exim Configuration Manager saves and cPanel updates can overwrite your custom ACL blocks unless you register them through cPanel's official Exim hooks.

Is Rspamd actually faster than SpamAssassin on a busy mail server?+

Generally yes for CPU-bound workloads — Rspamd's C-based scanning uses less CPU per message than SpamAssassin's Perl rule engine at high volume. On typical shared or reseller boxes the difference rarely shows up before other bottlenecks do.

Will my SpamAssassin Bayes training carry over to Rspamd?+

No. The two use incompatible Bayes database formats. Migrating means retraining Rspamd's Bayes classifier from scratch against a fresh ham/spam corpus, with a period of reduced accuracy while it learns.

Which control panels support Rspamd natively?+

DirectAdmin can map SpamAssassin-equivalent settings onto an installed Rspamd instance, and some newer panels ship it out of the box. cPanel and Plesk do not offer native Rspamd support.