RMail and Conbool compared.
Both prove delivery of an individual message, by different means. Conbool also covers file transfer and audit-proof archiving, from the same console. This page compares all three disciplines, with sources.
Modules
Nine modules, one console.
What RPost covers according to its public portfolio, and what it does not. The classification follows the vendor's material, not our opinion.
Based on rpost.com, rmail.com, registeredemail.com and RPost's help articles, retrieved in September 2026. Where they say nothing, this table says “not stated” rather than making a claim. What your contract covers is defined by your quote.
- MailGuardspam, phishing, BEC
- SecureMailS/MIME, OpenPGP, portal
- SecureFileslarge files
- Disclaimercentral signatures
- DMARC Reportsoutbound identity
- Archiveaudit-proof, WORM
- 365 Backupback up Microsoft 365
- Awarenessphishing simulation
- Continuitymail flow during outages
The scope
Three disciplines, not one.
Anyone evaluating RMail usually needs more than secure mail. Once files and retention enter the picture, the comparison shifts.
Secure mail
- RMail
- RMail encrypts, evidences delivery and lands straight in the inbox without registration.
- Conbool
- SecureMail encrypts with S/MIME and OpenPGP, with the message portal and a password-protected PDF as fallbacks, driven by rules. Every message yields an evidence document drawn from the chained log.
Both prove delivery, by different means
File transfer
- RMail
- File Share attaches large files to the mail, up to 1 GB depending on plan according to the vendor, retrieved through a download portal.
- Conbool
- SecureFiles has no size limit per file, secures recipients, runs an inbox for incoming files and optionally stores in your own S3 bucket.
This is where scope diverges
Archiving
- RMail
- RPost's public material does not state audit-proof archiving.
- Conbool
- Archive captures every message, keeps it immutable through the retention period, makes it searchable and governs access.
Conbool only
Two kinds of proof
What we mean when we say proof.
The words sound alike and mean different things. The difference decides which product fits your obligation.
Proof per message
According to the vendor the Registered Receipt is a forensic, timestamped record of delivery, content and time, built for disputes. If you have to evidence individual sends in court, this is a tool made for exactly that.
Since September 2026 Conbool maintains an evidence chain: every event relating to a message is logged in sequence, each entry carries the hash of its predecessor, and the head of the chain is sealed every fifteen minutes. An evidence document can be produced from it for any message. It carries no separate electronic timestamp; the times come from our own logging.
Proof across the record
Retention periods, WORM immutability, full-text search across the entire archive, four-eyes approval for access to other people's mailboxes, logged break-glass access and a deletion concept with evidence. That answers an audit which wants ten years, not one message.
An audit-proof archive of this kind is not stated in RPost's public material.
Sources: rpost.com, rmail.com and registeredemail.com, retrieved in September 2026. Registered Email, Registered Receipt, RMail and RSign are trademarks of RPost.
Evidence in detail
What a proof of delivery has to contain.
Since September 2026 SecureMail maintains its own evidence chain. Eight points where the two approaches differ.
In short: proof per message now exists on both sides. RMail relies on a patented procedure with its own timestamp, we rely on a chained log that can be recomputed in full at any time. For opening, the difference lies in the method: a tracking pixel can be switched off in the recipient’s mail client, logging in the message portal cannot.
Statements about RMail are taken from publicly available RPost sources, including registeredemail.com and the RPost Help Center (Registered Receipt, Open Receipt), retrieved in September 2026. Statements about Conbool describe SecureMail as of September 2026 and can be verified in a demo.
Recipient path
What arrives at the other end.
Here RMail is deliberately uncompromising, and that is a real argument. We solve it differently, with a rule per case.
RMail
According to the vendor delivery goes straight into the recipient's inbox, without registration and without a download. TLS with a selectable minimum version and message-level encryption that persists in the recipient's mailbox are named. S/MIME is mentioned but described as burdensome because of key exchange.
Conbool SecureMail
Where a certificate or key exists, mail is encrypted with S/MIME or OpenPGP, end to end into the mailbox. Where neither exists, the fallback applies: a link to the message portal that the recipient opens without an account and without registration, or a password-protected PDF. Which path applies is decided by a rule that also knows attachment, file type and size.
In short: RMail saves the recipient a click, Conbool gives you the choice of method per case and keeps the key-based path as the first path.
File transfer in detail
What happens when the file is too big for mail.
The most common reason to buy a product at all. Six points where the two paths differ.
File Share figures are taken from the RPost Help Center, the File Share article and the article on plans, service parameters and limitations, retrieved in September 2026. They depend on the plan, so have your scope confirmed in writing. SecureFiles figures are documented in our own documentation.
Retention
Where the message goes once it is delivered.
A delivery receipt says a message arrived. It says nothing about whether you can still find it in six years. That is exactly what an audit checks.
Immutable through the retention period
Retention periods per tenant, WORM storage, no deleting and no changing within the period, administrators included.
Internal mail too
A journal rule in Exchange captures messages between two of your own mailboxes that never pass a gateway. Without it, exactly that part is missing from the record.
Governed access
Full-text search across the record, access to other people's mailboxes only under four eyes, break-glass access possible and logged.
Deletion with evidence
After the period ends, data is deleted and the deletion can be evidenced. That is the other half of a retention obligation, and the half people forget.
RPost's public material does not state archiving of this kind. If you need it, you procure it separately there.
Contract and jurisdiction
Who processes your data, and under which law.
This comes up in every tender, and the easy answer is wrong here. RPost stores in the EU by its own account. The difference sits one level above, with the contracting party and the group.
In fairness: your mail does not automatically sit in the US with RPost. But if your requirement is that contracting party and group sit entirely within the EU legal area, a British entity under a US parent will not get you there. Since Brexit the United Kingdom is a third country with an adequacy decision, and that decision is reviewed periodically.
Source: rpost.com, privacy notice and the statement on technical and organisational measures, retrieved in September 2026. The same notice records that the EU-US Privacy Shield certification was not renewed. Check the processing agreement that applies to you, as details may differ by sales channel.
Honestly
What RMail has and we do not.
Two things you will not get here. If they are your reason to buy, we are the wrong vendor.
Patented receipt with timestamp
The Registered Receipt is patented, carries an electronic timestamp according to the vendor, and is described by RPost as admissible evidence of high evidential weight in European proceedings. Our evidence chain is chained, sealed and recomputable, but carries no separate timestamp. If you need exactly that established procedure, RPost is the right choice.
Electronic signatures
RPost offers RSign as a dedicated product for electronic signatures. We have none and integrate none.
In the same console
What you get on top here.
Beyond mail, files and archive, these modules share the admin portal, the audit log and the contract.
Inbound protection
Spam, phishing, BEC, an attachment filter with CDR and a retroactive threat scan that re-evaluates links after delivery.
Microsoft 365 backup
Mailboxes, calendars and files on a fixed schedule, plus writing users and groups back into Entra ID.
Continuity
Mail is accepted and stays readable when the mailbox system is down, and is delivered afterwards in a controlled way.
Awareness
Phishing simulation and training, optionally with defused real attacks taken from your own traffic.
Your own data centre
The same platform as a container stack in your own house, when the data must not go to a cloud.
Fits you
When Conbool is the better choice.
- You want mail, file transfer and archiving from one console instead of running three contracts side by side.
- The duty of proof covers both: the individual message and the archive over years, with retention periods, immutability, search and controlled access.
- The key-based path should be the first path, S/MIME and OpenPGP instead of a vendor scheme.
- You want a German contracting party and the data location named in the processing agreement.
- Cloud or your own data centre should stay your decision, with the same software.
- Large files should go out without a size limit and without a foreign cloud, optionally into your own S3 storage.
- Contracting party, group and data storage should sit entirely within German jurisdiction, without a detour via a foreign parent company.
- You need to prove when an encrypted message was opened, not only that it was delivered.
Fairness
When RMail is the right choice.
- An established, patented evidence procedure with its own timestamp is explicitly required, for instance because the opposing party insists on it.
- Electronic signatures belong to the same workflow and should come from the same vendor.
- Your recipients must under no circumstances open a portal, not even with one click.
- Filtering, archiving and backup are already solved elsewhere.
Frequently asked questions
Sources and fairness note
Statements about RMail are taken from publicly available vendor sources: rpost.com including its German edition, rmail.com and registeredemail.com, retrieved in September 2026. RMail, RSign, Registered Email and Registered Receipt are trademarks of RPost and we are not affiliated with RPost. Products change; have the terms that apply to your contract confirmed in writing. Statements about Conbool are described in our documentation and verifiable in a demo.
The File Share figures come from RPost's help articles. Those pages block automated retrieval while remaining publicly readable in a browser. Every figure there depends on the plan, so have your scope confirmed in writing before you base a decision on it.
Decide on your own case.
Tell us what you need to prove. If a patented delivery receipt with its own timestamp is your reason to buy, we will say so.