Legacy email archives don’t usually cause day-to-day problems – which is why so many organisations continue paying for them long after they’ve moved to Microsoft 365 or Google Workspace.
But just because something isn’t broken doesn’t mean it’s free. In fact, maintaining legacy archives like Mimecast, Enterprise Vault, or SourceOne can quietly drain time, budget, and compliance headroom year after year.
Here’s what that really looks like, and why migrating your archive sooner pays off.
1. You’re paying twice
Many organisations have already moved their live email to M365 or Google Workspace. But they keep their old archive platform running “just in case.” That means double licensing costs – one for your modern email service, and one for the legacy system you’re no longer actively using.
Over 3–5 years, this duplicated spend often exceeds the one-time cost of archive migration.
2. Storage costs creep up
Legacy archives aren’t lean. Deduplication is often weak, retention rules go stale, and PSTs keep reappearing. The result? TBs of unnecessary data accumulating – and costing you, whether on-prem or in the cloud.
Some hosted archive platforms charge per GB, per user, and per retrieval. The more data you store, the more it costs. Forever.
3. Support and maintenance aren’t cheap
Old systems don’t maintain themselves. They require patching, monitoring, license renewals, and time from your IT team. In some cases, vendor support is being phased out, meaning you’re paying premium rates for legacy SLAs – or relying on risky in-house workarounds.
4. Productivity takes a hit
Need an old email from a leaver’s archive? Waiting on IT to extract PSTs or retrieve legacy content? That time adds up – and slows everyone down.
Your archive should be searchable and self-serve, not a bottleneck.
5. Risk is expensive
Stale archives are a compliance nightmare. They’re harder to search, harder to audit, and more likely to contain data that should have been defensibly deleted.
In the event of a GDPR request, FOI query, or legal discovery, those risks can become real costs – in the form of staff time, legal exposure, or reputational damage.
The cost of keeping your archive might be higher than the cost of migrating it.
With Ultimate Migrator, you can move off expensive legacy platforms and into your modern email environment – securely, quickly, and without disrupting your users.
We’ll help you quantify the cost of staying put – and show you why “doing nothing” might be the most expensive choice of all.