SEPPmail and Conbool compared.
For encryption, filtering and signatures both cover the same ground. The difference starts where email security does not end: archiving, backup, awareness and staying operational during an outage.
Where both meet, and where they do not.
Nine modules, one platform, one contract. Four of them are covered by SEPPmail's public portfolio as well, four are not.
- MailGuardspam, phishing, BEC
- SecureMailS/MIME, OpenPGP, portal
- SecureFileslarge attachments
- Disclaimercentral signatures
- DMARC Reportsoutbound identity
- Archiveaudit-proof, WORM
- 365 Backupback up Microsoft 365
- Awarenessphishing simulation
- Continuitymail flow during outages
Classification based on the publicly described portfolio, seppmail.com and docs.seppmail.com, retrieved in September 2026. What your contract includes is defined by your quote.
Verifiable
Eight points that make the difference.
Every point is described in the public documentation and can be verified in a demo.
Audit-proof archive with WORM
Retention periods, immutability and four-eyes approval for access to other people's mailboxes. Journal rule or copy recipient, even without changing the MX record.
DocumentationBack up Microsoft 365 and write it back
Mailboxes, calendars and files on a fixed schedule, plus users and groups from Entra ID. Restorability is tested and documented once a year.
DocumentationContinuity when the mail server is down
Incoming mail is accepted and stays readable, replies keep flowing. After the outage the backlog is delivered into the mailbox in a controlled way.
DocumentationRetroactive threat scan
Links and attachments are re-evaluated after delivery. If the verdict changes, the platform reports the affected message.
DocumentationSIEM export as a live stream
Events go to Splunk, Microsoft Sentinel and QRadar. The audit log is the same across all modules, not one per product.
DocumentationMessage portal without an account
Recipients without a certificate open a link and reply in the browser. No registration, no self-chosen permanent password, a passphrase is optional.
DocumentationAttachment filter with CDR
Active content is stripped from documents instead of rejecting the message outright. File types and sizes are configurable per direction.
DocumentationGateway bypass is rejected
Direct send around the protection layer is detected and blocked. Otherwise mail reaches the mailbox unscanned and nobody notices.
DocumentationRecipient path
What a recipient without a certificate has to do.
The cryptographic substance is comparable on both sides. The difference is what the other party has to do.
Conbool message portal
- open the link in the message
- read the message in the browser
- reply directly, passphrase optional
SEPPmail GINA
- registration on first contact
- choose a password, needed again later
- or a per-message password over a second channel
Source: docs.seppmail.com, GINA registration types, Unique E-Mail Password and One-Time Password, retrieved in September 2026.
Operation
Cloud or your own data centre, your call.
Both run the same platform with the same modules. No reduced feature set, no second product.
Conbool Cloud
EU data centres on ISO 27001 certified infrastructure, a German contracting party, processing agreement under Article 28. First mailboxes go live within hours.
Conbool in your own data centre
The same platform as a container stack on a Linux host, all modules included. Data never leaves your premises, Switzerland included. Updates by click, no appliance image.
SEPPmail
Classically an appliance or virtual machine on site, alongside seppmail.cloud as a managed service, operated according to the vendor in Switzerland or Germany.
In detail
Six small things you only notice when they are missing.
Day-to-day it is not the headline features that decide, but what a rule can do once the case departs from the textbook.
Rules know about attachments
A rule can apply only with or only without an attachment, by file type or above a size. The type is detected from the file content, so a ZIP renamed to .pdf does not slip through. S/MIME without an attachment, a password-protected PDF with one, is a matter of two rules.
DocumentationInbound mail is decrypted and verified
At the gateway, before the message reaches the mailbox: decrypt S/MIME and OpenPGP, verify the signature, record the result. The filter then sees plain text instead of a sealed envelope.
DocumentationRelease methods per group
S/MIME, OpenPGP, PDF password and portal can be enabled individually and limited to groups. Finance gets the PDF, engineering gets the key.
DocumentationNot just Outlook
The add-in runs in Outlook classic, new and web, and there is a separate add-on for Thunderbird 128 or later. SEPPmail publicly describes an Outlook add-in.
DocumentationOther people's mailboxes only under four eyes
Looking into someone else's mailbox in the archive requires a second approval. Break-glass access stays possible but leaves a trace.
DocumentationThe same software in your own house
Running it in your own data centre is documented and works as a container stack, with the same modules and updates by click.
DocumentationFits you
When Conbool is the better choice.
- Encryption, filtering, archiving, backup and awareness should sit in one console, with one audit log and one contract instead of five procurements.
- Your recipients should not have to set anything up: open a link, read, reply, no account and no registration.
- You need evidence: a WORM archive, four-eyes approval for access to other people's mailboxes and an event log that lands in Splunk or Sentinel.
- Mail has to keep flowing even when Exchange is down: continuity accepts, keeps readable and delivers afterwards.
- You want the choice between cloud and your own data centre without buying a different product for it.
Fairness
When SEPPmail is the better choice.
- An established appliance runs, is written off and the team knows it inside out.
- A Swiss contracting party is fixed in your compliance strategy and running it on your own premises is out of the question.
- GINA workflows with registration or password handover over a second channel are baked into processes and training.
- Archiving, backup and awareness are already solved elsewhere and should stay that way.
Frequently asked questions
Sources and fairness note
Statements about SEPPmail are taken from publicly available vendor sources, seppmail.com and docs.seppmail.com, retrieved in September 2026. Products change; have the terms that apply to your contract confirmed in writing. Statements about Conbool are described in the documentation and verifiable in a demo.
See it in your own setup.
One hour of demo on your mail flow, in the cloud or in your own data centre. After that you know which of the nine modules you actually need.