We shipped Octeth v5.9.0 today. Forty-six commits across 8 days of development — 12 new features, 27 bug fixes, and automatic SSL certificate management finally handled the right way.
This release has a clear through-line: give you better tools to improve results, better visibility into your infrastructure, and better insight into your list health. The three headline features each address something different, but they all come back to the same underlying goal — making Octeth a more capable platform for people who take email seriously.
Let me walk through what changed.
A/B Campaign Testing is Finally Here
This has been the most-requested feature we've had sitting in the backlog. Starting today, you can set up multi-variate A/B tests directly inside the campaign creation flow.
The experience works the way it should: create multiple content variations within a single campaign, define your test audience size, send the test, and let Octeth identify the winner. The winning variation then goes out to your full list automatically.
A few things worth knowing about how we built this:
Winner detection is accurate. One of the subtler problems with A/B testing is floating-point math. When you're comparing open rates or click rates across variations with different audience sizes, rounding errors can actually pick the wrong winner. We solved this using integer cross-multiplication instead of floating-point division. It sounds like a detail, but it's the kind of detail that matters when the difference between two variations is close.
The workflow is integrated, not bolted on. A/B campaigns appear in a dedicated browse and overview screen, so you're not hunting through your regular campaign list trying to figure out which sends were tests. Variation previews are built in, one-click variation duplication saves setup time, and the whole experience follows the same patterns as the rest of the campaign builder.
Seed lists are excluded. If you use seed addresses for monitoring, they're excluded from A/B variation distribution. This keeps your test data clean.
For anyone running regular campaigns, A/B testing is one of those features that compounds over time. Each send becomes a data point that informs the next one. Subject line performance, content layout, send timing — you build up a real understanding of what works for your specific audience instead of going on intuition.
Email Gateway: Rebuilt From the Ground Up
The Email Gateway UI has been completely redesigned following Octeth's modern interface standards. If you've been managing sending infrastructure across multiple domains, you'll notice the difference the moment you open it.
The previous interface made it too hard to get a quick read on what was happening across your sending setup. The new one fixes that.
Account-level dashboard — A top-level view of your sending health across your entire account. The health summary you need, without drilling into individual domain configurations to piece it together.
Cross-domain event log — This is the one I'm most pleased with. You can now trace delivery events across all your domains in a single unified view. Previously, tracking down a delivery issue meant checking each domain's event log separately. Now it's one place, filterable, with event data that maps exactly to what your system actually tracks. Field names, filter values, and index windows are all corrected in this release.
User-area access — Quick access to Email Gateway right from the main navigation, so you're not navigating through admin menus to get to infrastructure you're checking regularly.
Webhook security — We also tightened SSRF protection on webhook configurations. This is the right thing to do and not worth skipping on security grounds.
For agencies managing sending infrastructure across multiple client domains, the cross-domain event log alone substantially changes how you approach troubleshooting. Problems that used to take significant time to diagnose now surface immediately.
List Freshness Report
Good deliverability starts before you send. It starts with knowing the state of your lists.
The new List Freshness Report gives you a clear picture of engagement recency across your subscriber lists. It tracks how recently subscribers have engaged within a rolling 90-day window, so you can see at a glance which lists are healthy, which segments are going stale, and which lists need re-engagement campaigns or cleanup before you send to them again.
The threshold calculations are robust against incomplete or missing data — something that matters in production environments where list data isn't always perfectly clean. We also aligned the window calculations properly to the full 90 days, which makes the engagement distribution accurate rather than artificially truncated.
Sending to disengaged subscribers is one of the fastest ways to damage your sender reputation. Inbox placement depends on engagement signals, and ISPs pay close attention to whether your recipients are actually opening and clicking. The List Freshness Report makes list hygiene a proactive practice instead of a reactive one. You see the problem before it hits your deliverability.
Automatic SSL via Caddy
We've replaced the certbot-based SSL system with Caddy's on-demand TLS.
New domains now get SSL certificates provisioned automatically. Renewals happen without any intervention. You don't have to think about certificate management, and you won't get caught by a certificate that expired because a cron job failed silently three months ago.
One thing to note: the certbot cron is disabled in this release. If you're currently running certbot for SSL, you'll want to migrate to the Caddy setup. This is a breaking change for that specific workflow — it's worth being clear about it. The Caddy approach is significantly better in practice, but the migration is a conscious step.
CLI and Developer Tools
Two additions for those managing Octeth infrastructure day-to-day:
errors:analyze command — This new CLI command deduplicates and summarizes your error logs. Triaging production issues used to mean sifting through repetitive log entries to find distinct error patterns. This command does that work for you, surfacing what actually needs attention instead of showing you the same error repeated a thousand times.
RabbitMQ status display — The queue overview now renders as a formatted table. Not a dramatic change, but it makes the processing health of your queue genuinely readable at a glance instead of a wall of text.
27 Bug Fixes
The bug fix list is substantial. A few worth highlighting:
A/B winner detection — The cross-multiplication fix mentioned above is the most impactful. The previous floating-point approach could select the wrong winner in close results.
API key creation after deletion — Creating a new API key after previously deleting one was failing. Fixed.
Email Gateway event mapping — Corrected field names, filter values, and index windows across event tracking. The gateway events you query now reflect what your system actually captured.
Link proxy health check — Infrastructure health monitoring for the link proxy service was broken due to a dependency on wget in environments where it wasn't available. Switched to curl, which is reliably present.
List Freshness thresholds — Hardened against corrupt or missing threshold configuration data. The report now handles these cases gracefully instead of breaking.
v5.9.0 is a tightly scoped release — eight days of development, a clear set of goals, and a lot of execution. The A/B testing feature alone has been in demand for a long time, and I'm glad we were able to ship it in a form that's genuinely well-considered rather than a quick implementation. The gateway redesign and List Freshness Report round out a release that meaningfully improves the platform across campaign management, infrastructure visibility, and list health.
If you're an existing Octeth client, login to the Octeth Client Area to download v5.9.0.
If you're evaluating Octeth or want to learn more about what it can do for your organization, fill in our contact form and we'll be in touch.
Octeth is a self-hosted email marketing platform built for businesses and agencies that need full control over their email infrastructure. Learn more at octeth.com.
