mail:u secure – OpenSSL upgrade to 3.5 (LTS)

At mail:u secure we maintain every security-critical component with care and foresight. The recent upgrade to OpenSSL 3.5 (LTS) shows how we put that principle into practice.

mail:u secure processes confidential communication around the clock – for organisations and teams where reliability is non-negotiable.

Keeping that communication safe today and in the years to come requires solid technical foundations. One of those building blocks is OpenSSL, the crypto library that powers encryption, signatures and secure transport.

We rely on OpenSSL continuously, so it matters which version we use and how long it will receive maintenance. The previous LTS line 3.0.x is supported until 2026. Moving to 3.5 (LTS) extends that window until 2030, delivering planning certainty independent of OS releases, compiler changes or new regulatory demands.

This upgrade was not about solving an urgent problem – it was a deliberate choice to create stability early.

Modern software stacks consist of many building blocks. A few are visible, most run quietly in the background. Those invisible components are often the most critical for security – and exactly where many organisations look too late.

Lifecycle management for us means:

• tracking versions and support timelines
• planning early instead of improvising later
• rolling out changes in a controlled fashion before they become mandatory
• reducing the impact of EOL phases

We treat lifecycle management as an ongoing discipline, not an occasional task. Systems built on obsolete foundations are only stable on the surface. Once a critical component reaches end of life, every downstream update becomes harder, riskier and more time-critical.

Executing upgrades at the end of a support period is rarely ideal. There is more deadline pressure, test windows shrink and dependencies often change at the same time.

Waiting until the last minute means falling behind technically – the exact moment when outages, incompatibilities or rushed fixes appear. We avoid that risk. Acting early lets us:

• complete full test cycles
• document impacts cleanly
• plan rollouts deliberately
• define fallback paths
• prevent service interruptions

It is not spectacular, but it is essential – and one reason why mail:u secure runs so reliably. We do not wait for a lifecycle to end; we stay ahead of it.

OpenSSL 3.5 (LTS) might look minor from the outside. For us it represents a broader principle: we take care of the fundamentals – early, continuously and without panic.

That is how mail:u secure remains both functional and technically resilient over time. Security is not a single measure; it is consistent stewardship. That is exactly how we operate our systems.