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A few years ago, having a dedicated email ‘hygiene’ service to run alongside your Microsoft 365 environment was ‘essential’, with solutions like Mimecast and Proofpoint providing advanced anti-spam, anti-phishing, email journaling, eDiscovery, and so on.

Now, with continued investment from Microsoft into its cloud protection, data retention and eDiscovery capabilities, more and more organisations are reviewing their options as to whether they still need a separate service and deciding to make the move.

We have carried out many migrations from third-party journaling services over the last few years, so read on for our tips to help with your move – especially if you’re thinking of moving your journal into Microsoft 365 – which is like fitting a round peg into several square holes!

What’s the best way to get our data out of our journal vendor?

There are basically 3 routes to extracting your data out of Mimecast or Proofpoint:

1. Ask Mimecast or Proofpoint for an Extract of your Journal files

Now, call me a cynic, but even if a cloud vendor could make it easy for you to bulk extract your data when you want to move on, providing this facility would be low on their list of priorities. 

That’s why most migrations start with asking your journaling service provider for an extraction of your email journal.

By default, this is typically a paid-for service carried out by staff at your journal service provider, and results in files that get shipped to you on a removable disk or more likely these days over FTP.

Also make sure you’re sitting down for when they tell you the fee for your extraction.

2. Do the extraction yourself

3. Automate the extraction with specialist tools/partner

Extraction is Only Half the Migration Story

Getting your data out of your email journal is only the first step to moving your data from Mimecast or Proofpoint.

Once your journal files have been extracted, they still need to be reconstructed, validated and imported into the target platform.

And this is where many projects become more complicated than expected.

Depending on the extraction method used, organisations can end up with:

• Raw journal files that aren’t directly ingestible into Microsoft 365
• Missing metadata
• Problems preserving BCC recipients and distribution list information
• Difficulties proving chain-of-custody for compliance purposes

In other words, extraction alone doesn’t complete the migration.

The real objective is ensuring that the data becomes:

• Searchable
• Discoverable
• Retention-managed
• Legally defensible
• Accessible to users and compliance teams

…inside the new platform – which for our client base, is typically Microsoft 365.

To reiterate, this is where having a partner to manage your end-to-end migration can really pay dividends, as the first 2 options discussed above only address part of the job in hand!

Here’s how to decide on your optimal journal migration approach:

Choose the approach that best fits your volume, timeline and governance requirements.

It’s also worth considering the balance between speed, cost and operational overhead when comparing vendor-managed extractions with tool-based/partner-led extraction approaches from platforms like Mimecast or Proofpoint.

For example, if you’re working towards a tight deadline ahead of a Mimecast renewal, the ‘fastest’ route isn’t always obvious. In some cases, organisations choose to reduce their Mimecast licensing footprint and pay a lower ongoing fee to retain journal access while a longer-term migration project completes in the background.

A fully DIY journal migration

If you’re moving a relatively small subset of journal data – and have the internal bandwidth to oversee manual exports (see point 2 above), validation and imports into the target platform.

This can work well for smaller, lower-risk projects where timelines are flexible and governance requirements are relatively straightforward.

Vendor-managed extraction + Partner ingestion

If you’d prefer Mimecast or Proofpoint to manage the extraction process directly, and are comfortable working within their commercial models and timelines, a vendor-managed approach may make sense.

However, it’s important to remember that extraction is only one stage of the project. As we said earlier, you’ll still need a strategy for reconstructing and migrating the extracted data into the target platform – which often means involving a migration specialist partner.

End-to-end extraction + Microsoft 365 ingestion

For larger-scale projects, particularly where data needs to be migrated into specific Microsoft 365 locations to support accurate eDiscovery, retention and compliance requirements, an end-to-end migration approach is usually the most effective route.

This is especially relevant where:

• Large journal volumes are involved
• Tight timelines exist
• Metadata and chain-of-custody must be preserved
• Data needs to land in specific Microsoft 365 destinations for governance purposes

In these scenarios, working with a migration partner (like Essential) can significantly reduce project risk and operational overhead.

By all means, get in touch for a chat – there are still plenty of things to consider between extraction methods and choices around how you ingest into Microsoft 365 that are worth discussing before deciding on the right approach for your company.

For example, see the section below that outlines how Microsoft 365 doesn’t have a conventional journal to migrate into.

Check out the rest of our other frequently asked questions lower in this article.

These are your 3 migration options ‘at a glance’

	Approach	How it works	Pros	Cons
Migration Approaches	Native export (admin / eDiscovery)	Manual export from Mimecast UI/tools	✔️ No third-party tooling required	✖ Slow and heavily throttled ✖ Batch limits on large exports ✖ Limited progress tracking ✖ Data may still require reconstruction before Microsoft 365 migration
	Vendor-managed extraction	Mimecast extracts and releases archive data	✔️ Managed directly by the vendor ✔️ Reduced internal effort	✖ Expensive at scale ✖ Slow release cycles ✖ Continued vendor dependency ✖ Data still needs migrating into the target platform
	Automated extraction + Microsoft 365 migration	Extract journals → reconstruct mailbox data → migrate into Microsoft 365	✔️ Complete end-to-end migration ✔️ Automated reconstruction and ingestion ✔️ Avoids large vendor exit fees ✔️ Preserves metadata and auditability ✔️ Better alignment with Microsoft 365 retention	✖ Requires specialist tooling and migration expertise

Should we migrate everything in our journal?

Lots of customers decide to migrate literally everything from the point that their journaling service ‘kicked in’.

You may be able to migrate less than this, however.

Our tip is to seek advice from your legal team on how far back you need to go – it may not be as far back as you’ve been maintaining your journals.

And, if you’ve already applied the Microsoft 365 retention policies that mimic the effect of journaling, when was this done?

With this information you will be able to perform a journal extraction that falls within two dates, resulting in lower costs and a shorter migration time.

How quickly can we migrate our email journals?

If your migration involves the Mimecast extraction service, you’ll be reliant on someone at Mimecast physically extracting data on your behalf, the timelines for extraction will be the biggest bottleneck in your move.

For example, we’ve heard of a client that had to wait 8 months to get a paid-for extract of less than 40GB from their email protection vendor.

As discussed, you can reduce overall migration timelines (and costs) by being selective in what you extract from Mimecast.

You can also use a ‘last in first out’ approach to speed up your migration. For example, you might prioritise emails less than 2 years old for your migration, and then top up beyond this later (or just let it ‘age in place’).

Our new direct extraction service also uses multiple tasks to gets the optimal extraction performance.

Rest assured, once you have your data out, it can be ingested into Microsoft 365 at a significantly faster rate!

Do we need to worry about chain of custody?

Any time an electronic record is physically moved between storage devices or locations, there’s potential to introduce risk. For example:

• If your data has be transferred via an interim storage device during the migration process, could it be tampered with or lost owing to a hardware corruption?
• If your data needs to be extracted into a neutral format before it can be re-imported into the new journal, could this lead to inadvertent data loss, such as mis-mapping of content or meta-data?

For example, if your migration route starts off with a physical extraction carried out by Mimecast personnel, into a general email format, it’s difficult to get the forensic, end-to-end assurances we would typically like.

We recommend that you get an accurate indication of how much data will be extracted and ensure this tallies up with what is delivered to you, and what gets migrated into Microsoft 365.

Ideally an audit should be produced to prove due diligence during each stage of your migration.

Again, we can address both the extraction stage and the tracking of extracted data in a more reliable and streamlined fashion.

Does Microsoft 365 have an equivalent journal?

No!

As we’ve already said, migrating a conventional email journal (such as that provided by Mimecast) into Microsoft 365 not easy.

This is because Microsoft 365 doesn’t offer a ‘like-for-like’ journal service.

You can read more about how Microsoft 365 replaces the role of a journal in this article. We also have a cute pirate-based explainer video here>

The key point is that migrating journals into Microsoft 365 is not straightforward, and having a knowledgeable partner to work with will help you achieve the best outcomes.

Can we just switch over to using Microsoft 365 email hygiene services?

Updating your MX records to divert your email traffic from Mimecast to Microsoft 365 is relatively easy, but check before you ‘throw the switch’.

Make sure that you have all the right retention and data governance policies in place AND that you are 100% happy with the email protection options you’ve configured in Microsoft 365.

To ensure this is the case for your organisation, we can help you analyse your security needs and make recommendations for ensuring Microsoft 365 is configured correctly before you jump ship.

Our team can provide help every step of the way, from thinking through the plan, liaising with Mimecast, executing the migration according to your wishes and reporting on migration status.

For a chat with one of our specialists, please get in touch.