Mimecast Aware vs Smarsh vs Proofpoint vs Microsoft Purview: capturing and searching Teams and Slack
If you need to keep, search and produce what people say in Microsoft Teams and Slack, for a subject access request, an investigation, a legal hold or a regulator, four products make most shortlists: Mimecast Aware, Smarsh, Proofpoint and Microsoft Purview, with LeapXpert often mentioned alongside. They are not built for the same job. This guide sets out who each one is really for, where each is strong, and why we usually recommend Aware for UK enterprises outside the trading floor. C4C is an accredited Mimecast partner, disclosed up front.
Start with what you have to do with the data. If you are a broker, bank or trading firm that must record and supervise every channel, including mobile, WhatsApp and voice, Smarsh and Proofpoint are built for that. If your people work only in Teams, you own E5 and requests are rare, Purview can be enough. If you are a UK enterprise that needs to answer subject access requests, investigations and legal holds across Teams, Slack and email quickly, Mimecast Aware is usually the best fit, and it is what we recommend. Whichever you choose, capture has to be running before the request arrives.
Collaboration data is now where decisions, opinions and personal data live, and it is edited and deleted all day. Our guide to subject access requests in Teams and Slack covers what the law demands. Our Aware vs Purview eDiscovery comparison goes deep on the Microsoft question. This guide widens the field to the products buyers actually shortlist.
Who each one is built for
Mimecast Aware is a collaboration governance and eDiscovery platform for the wider enterprise. It captures Microsoft Teams, Slack, Webex and Zoom Team Chat, keeps the full conversation including edits and deletions, and its Search and Discover tool runs one query across Teams, Slack, Google Chat, Viva Engage and, for Mimecast archive customers, email, with export of just the data subject's own messages for a subject access request. Sources: Mimecast Aware, Mimecast, 2026.
Smarsh is built, in its own words, for financial firms. It captures more than 100 channels, including Teams chats, channels and meetings, carrier SMS, WhatsApp and other mobile apps, and stores them in immutable WORM storage for SEC 17a-4, with AI driven supervision against SEC, FINRA and FCA rules. Sources: Smarsh Capture, Smarsh for Microsoft Teams, Smarsh Archive.
Proofpoint Digital Communications Governance is built for highly regulated and litigious organisations. It captures more than 80 channels, including Teams, Slack, Zoom Meetings, Webex, AI assistants and some mobile channels, with an archive supporting SEC 17a-4 and supervision tools for financial regulators. Sources: Proofpoint Capture, Proofpoint Archive.
Microsoft Purview is the native answer for Microsoft 365. Its eDiscovery searches Teams chats, channels, meeting chat, recordings and transcripts, with review sets and analytics in the premium tier that comes with E5. Slack and Zoom only arrive through partner connectors. Sources: Microsoft Learn, Teams content in eDiscovery, Microsoft Learn, eDiscovery.
LeapXpert is different again. It lets employees message clients on WhatsApp, iMessage, SMS and similar apps from a governed business app, captures those conversations, and exports them to an archive. It does not archive internal Teams or Slack chat. Source: LeapXpert recordkeeping.
Side by side
| What matters | Mimecast Aware | Smarsh | Proofpoint | Microsoft Purview |
|---|---|---|---|---|
| Built mainly for | Enterprise investigations, subject access requests, legal hold and conduct | Financial services recordkeeping and supervision | Regulated and litigious organisations, especially financial services | Microsoft 365 compliance inside the tenant |
| Teams | Yes, including edits and deletions | Yes, chats, channels, meetings, Teams Phone and Copilot | Yes, chats, channels and meeting chat | Deepest, including recordings and transcripts |
| Slack | Yes, through the Slack Discovery API, or export upload for Business+ | Yes | Yes | Only through a partner connector, converted to email format |
| Zoom | Zoom Team Chat | Yes | Zoom Meetings and Contact Center | Only through a partner connector |
| Mobile, SMS and WhatsApp | No | Yes, including carrier SMS and WhatsApp | Some mobile channels and WhatsApp | Only through partner connectors |
| One search across email and chat | Yes, Search and Discover, with subject only export for SARs | Yes, across captured channels | Yes, across captured channels | Yes, within Microsoft 365 |
| Regulated supervision | Conduct and risk detection, with supervision in higher tiers | Core strength | Core strength | Communication Compliance, needs E5 level licensing |
| SEC 17a-4 WORM claim | Made for email, not stated for collaboration data | Yes | Yes | Yes, with Preservation Lock configured |
| How it is priced | Per user, covering all available integrations | On quote | On quote | Inside E5 or add ons, plus partner fees for Slack and Zoom |
Taken from each vendor's own pages and Microsoft Learn, checked 5 October 2026. Channel lists change, so confirm the channels you need before you buy.
Every third party tool, Aware, Smarsh and Proofpoint alike, captures Teams through Microsoft's export APIs. Microsoft says earlier versions of edited messages are only available where a Teams retention policy is in place, and messages users delete can be reached for up to 21 days. Source: Microsoft Learn, Teams export APIs. So whichever tool you choose, set a Purview retention policy for Teams and keep capture running continuously. A tool switched on after a request lands cannot give you back what was edited or deleted before.
Where each one wins
- Smarsh wins on breadth. If you must record WhatsApp, carrier SMS, iMessage, voice or Bloomberg alongside Teams, and supervise them against FCA or SEC rules, nothing else on this list covers as much.
- Proofpoint is the other mature regulated option, with wide channel coverage including AI assistants and Zoom Meetings, and it makes most sense if you already run Proofpoint for email security.
- Microsoft Purview wins on Teams depth and cost when it is already licensed. Meeting recordings, transcripts and Copilot interactions are covered natively, and the data never leaves the tenant. Its weak spots are Slack and Zoom, which need a separate partner subscription and are converted into email format, and the premium features, which need E5. Source: Microsoft Learn, archiving Slack data.
- LeapXpert wins a different contest: giving client facing staff a sanctioned way to use WhatsApp and iMessage. It sits alongside an archive rather than replacing one.
Why we usually recommend Mimecast Aware
Most of the organisations we work with are not trading floors. Their problem is answering a subject access request on deadline, running an HR or insider investigation, or placing a legal hold, across Teams and Slack, without turning each one into a project. That is the job Aware is built for.
- Built for the request, not the regulator. Search and Discover starts from keywords or a person rather than custodians, shows result counts as you build the query, and exports only the data subject's own messages for a subject access request. Source: Mimecast, 2026.
- The conversation as it happened. Aware keeps edits, deletions, reactions and threads, so what you produce is what was said, not what was left. For Slack it uses the Discovery API, and Business+ customers can upload Slack exports. Source: Aware for Slack.
- One search across chat and email. Teams, Slack, Google Chat and Viva Engage, plus email for Mimecast archive customers, in a single query, which is what a subject access request actually asks for.
- Simple to buy and quick to run. Per user pricing covers all available integrations, with no counting connectors, and Mimecast says it can be implemented in hours. Sources: Mimecast Aware, Mimecast, 2026.
We are equally clear about its limits. Aware does not capture mobile messaging or WhatsApp, its Zoom coverage is Zoom Team Chat rather than meetings, and Mimecast's SEC 17a-4 claims are made for email. Source: Aware for Zoom. If those matter to you, a regulated platform such as Smarsh or Proofpoint belongs on your shortlist, and we will say so.
Who we are. C4C Group is an independent UK technology consultancy and an accredited Mimecast partner. We supply, implement and support Mimecast Aware, and this guide recommends it deliberately for the enterprise problem it fits. We do not sell Smarsh, Proofpoint or LeapXpert, and we will tell you if one of them, or Purview alone, is the better answer. Ask us which fits your organisation.
Not sure which tool fits your Teams and Slack data?
Tell us which platforms you use and what you need to do with the data. We will tell you honestly whether Purview is enough, whether Aware fits, or whether you need a regulated platform instead.
Prefer email? Reach us directly at hello@c4cgroup.co.uk.
Frequently asked questions
What are the alternatives to Mimecast Aware?
The main alternatives are Smarsh and Proofpoint Digital Communications Governance, both built mainly for regulated financial services supervision and covering 80 or more channels including mobile and WhatsApp, and Microsoft Purview, which is native to Microsoft 365 and deepest on Teams. LeapXpert is often mentioned but is a sanctioned client messaging platform for WhatsApp and iMessage that hands records to an archive, not a Teams or Slack archiver.
Is Mimecast Aware or Smarsh better?
They are built for different jobs. Smarsh is built for financial firms with recordkeeping and supervision duties across 100 plus channels, including carrier SMS, WhatsApp and voice, with SEC 17a-4 WORM storage. Aware is built for the wider enterprise problem: answering subject access requests, investigations and legal holds across Teams, Slack, Google Chat, Viva Engage and email with one search. For a UK enterprise that is not a broker or trading firm, Aware is usually the better fit.
Can Microsoft Purview archive Slack and Zoom?
Not natively. Microsoft Purview brings Slack and Zoom in through partner connectors, such as 17a-4 DataParser, which converts Slack data into email format and imports it into mailboxes, with a separate account required with the partner. The Veritas connectors were retired in June 2024. Purview is strongest on Teams itself, including meeting recordings and transcripts.
Is LeapXpert an alternative to Mimecast Aware?
Not really. LeapXpert lets employees message clients on WhatsApp, iMessage, SMS, WeChat and similar apps from a governed business app such as Teams or Slack, and captures those conversations for compliance. It does not archive internal Teams or Slack chat, and it exports records to an archive rather than being one. It solves the off channel messaging problem, which is complementary to Aware rather than a replacement for it.
Can any tool recover Teams messages deleted before it was installed?
Only within narrow limits. Microsoft says messages users delete in Teams can be accessed through its export APIs for up to 21 days, and earlier versions of edited messages are only kept where a hold or retention policy is in place. Every third party tool, including Aware, Smarsh and Proofpoint, relies on those APIs for Teams. So capture and a Purview retention policy need to be running before a request or dispute arrives.
Is C4C independent if it recommends Mimecast Aware?
C4C is an accredited Mimecast partner and supplies, implements and supports Aware, and we disclose that on every page that recommends it. We do not sell Smarsh, Proofpoint or LeapXpert. We will still tell you when one of them, or Purview on its own, is the better fit, for example for a broker that must supervise WhatsApp and voice.