The lack of archiving
for Microsoft 365
Achieve GoBD compliance.
every email in 1-2 seconds .
Comply with § 147 AO • Reduce M365 storage costs • Open Source from Germany
1–2 seconds
Search time for millions of emails
M365 alone does not fulfill § 147 AO
Every company subject to tax in Germany is legally obliged to retain tax-relevant emails for 10 years (§ 147 of the German Fiscal Code, specified by the GoBD).
Microsoft Purview is an e-discovery tool for compliance cases. It does not provide an audit-proof archive with verifiable tamper detection, as required by the German principles of proper accounting (GoBD). Microsoft does not provide a system component for the procedural documentation required by GoBD.
Benno MailArchiv is the missing archiving component that complements M365 for tax-related retention requirements.
Why Microsoft 365 alone is not enough
M365 is an excellent collaboration platform – but not a GoBD-compliant long-term archiving solution for tax-relevant emails.
Purview ≠ Mail archive
Microsoft Purview is an e-discovery tool for rare legal cases – not a productive archive for 1,000 end-user searches daily.
No procedural documentation
GoBD-compliant archiving requires process documentation. M365 does not provide a system component for this.
No end-user access
Purview is only accessible to IT and compliance officers. Regular employees cannot search independently.
Expensive storage costs
Keeping emails in M365 is expensive. Deleting them risks violating GoBD regulations. Without an external archive, there's no way around it.
Expert assessment: E-discovery specialists like PRISMlit and iCognition confirm: Purview is designed for e-discovery purposes – not as a GoBD-compliant long-term archive. Microsoft itself describes Purview as a compliance and e-discovery solution – not as an archiving system according to German tax law. → PRISMlit analysis
The 4 key benefits for M365 users
Benno complements M365 – not competition, but the missing component.
Fulfill tax-related retention obligations
Section 147 of the German Fiscal Code (AO) mandates the retention of tax-relevant emails for 10 years. Benno meets the technical GoBD requirements through verifiable manipulation detection via cryptographically secured journal linking.
Productive e-discovery in 1–2 seconds
Benno offers productive e-discovery for everyday use. Even with millions of archived emails, all employees can find any email – including attachments of any kind – in 1–2 seconds via web browser.
Reduce M365 storage costs
Benno archives all M365 emails in a tamper-proof manner via journaling. This allows your users to delete old emails in Outlook without the risk of losing emails that must be archived. Mailbox quotas and M365 storage costs are reduced.
Centrally archive all email systems
Many companies run M365, Exchange on-premises, Zimbra, or legacy systems in parallel. Benno archives all sources in a central archive – without expensive third-party connectors.
Microsoft Purview vs. Benno MailArchive
Not competitors – but different tools for different tasks.
criterion
Microsoft Purview
Benno MailArchiv
Sources: PRISMlit, Nexcom, iCognition, Microsoft documentation.
Integration with M365
in 3 steps
Setup in 5–10 minutes via journaling. No downtime, no software installation.
Activate journaling rule in M365
Set up Exchange Online journaling in about 5 minutes. All emails are forwarded to Benno as journal copies. Originals remain in M365.
Benno receives & archives
Benno receives the journal copies, indexes them completely (including attachments in 1,300+ formats) and ensures integrity via SHA-256 checksums.
Users utilize self-service search
All employees can search instantly via their browser. Results in 1–2 seconds. Delegated search and granular rights management included.
Key features at a glance
Permalink system
Audit-proof links to every archived email – for legally sound evidence.
Full-text search in attachments
Over 1,300 file formats are fully indexed and directly searchable.
Integrity check
Every email is cryptographically secured. Manipulations are detectable during integrity checks.
Audit trail
Who searched for which email and when? Complete traceability for tax audits.
Multi-source archiving
M365, Exchange On-Premise, Zimbra, Google Workspace, Postfix – all in one archive.
open source-based
Based on AGPLv3. No vendor lock-in – switch to self-hosting at any time.
What Benno users are saying
Over 5,000 organizations trust Benno MailArchiv.
"I have never operated software that so reliably and painlessly simply does what it is supposed to do."
Dr. Thomas Bleek
Helmholtz Centre Potsdam
"Anyone who tries to quickly search for something in Outlook is out of luck. Benno MailArchiv finds the message you're looking for in fractions of a second."
Meike Maria Lücke
elbfeder communication
“We have been using Benno MailArchiv for our 1200 users for several years and are extremely satisfied. The outstanding feature is the incredibly fast retrieval of any email.”
Dr. Sven Zimmermann
Görlitz Municipal Hospital
“For us, the incredibly fast search function in Benno MailArchiv is indispensable. It saves us a lot of time when searching for information and emails.”
Frank Höcker
Höcker Polytechnik GmbH
Transparently calculated
Self-hosting or fully operated cloud service – the choice is yours.
Self-Hosting
For companies with their own IT infrastructure
per year (5 mailboxes, Small Business Edition)
- Standard Edition: from €6/mailbox/year
- Enterprise Edition: from €9.20/mailbox/year
- All features without restrictions
- Open Source-based (AGPLv3)
- Own servers, full data control
- Technical GoBD requirements met
Benno Cloud Enterprise
Fully operated managed service
by archived storage (GB/month)
- No mailbox size limits
- Operations in Germany (Hetzner)
- 3-fold redundancy, geo-redundancy
- Process documentation (system component) including
- Professional support included
- 95–99% of GoBD implementation services
Frequently Asked Questions
Why do I need Benno when I have Microsoft Purview?
Purview is an e-discovery tool for rare legal cases – not designed as a GoBD-compliant long-term archive. Benno fills this gap: audit-proof archiving with a 1–2 second search time for all employees.
Does Benno comply with the GoBD (Principles for the Proper Keeping and Use of Books, Records and Documents in Electronic Form and for
Benno meets the technical requirements of the German Generally Accepted Accounting Principles (GoBD). According to GoBD section 21, the taxpayer bears the tax responsibility. With Benno Cloud Enterprise, we handle 95–99% of the implementation work.
How does the integration with Microsoft 365 work?
Via Journaling: Set up a journaling rule in Exchange Online (approx. 5 minutes). All emails will be forwarded to Benno as journal copies – originals remain in M365. Total setup time: 5–10 minutes.
How much does Benno cost?
Self-hosting: From €80/year (5 mailboxes). Benno Cloud Enterprise: Usage-based on storage (GB/month), no mailbox limits. Benno often pays for itself through the savings on M365 storage costs.
Where is my data stored?
Cloud Enterprise: Exclusively in Germany with triple redundancy and geo-redundancy. Self-hosting: You completely determine the storage location yourself.
Ready to close the archiving gap?
Try it free for 60 days – no risk.
Or give us a call: Personal consultation for your M365 environment.
* According to § 147 AO and GoBD Rz. 21, the taxpayer bears sole responsibility for proper archiving under tax law – even with complete technical outsourcing. Benno MailArchiv meets the technical GoBD requirements. With Cloud Enterprise, LWsystems GmbH & Co. KG handles the vast majority of the implementation work. "95–99%" is a communicative assessment of the practical division of tasks.