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Secure Email Hosting in Germany

Put your email infrastructure in trusted hands. Whether ten or ten thousand mailboxes, we manage environments of all sizes, provide GDPR- and ISO 27001-compliant email hosting, and advise you on implementing customized on-premises or in-house solutions.

Ideal for SME

Email Hosting in Germany

Discover the peace of mind with our secure and efficient email hosting service, based in Germany, known for its strong data privacy laws. Our service combines speed and safety, ensuring easy access to your emails from any device while protecting your inbox from spam and harmful content. Hostzero's email servers use our own hardware and fully comply with BSI's Technical Guidelines TR‑03108‑1 and TR‑03182. We are also happy to advise you on topics such as email signing and encryption via PGP or S/MIME.

Storage

100 GB per mailbox. With daily backups, no strings attached

Spam Filters

State-of-the-art AI-powered spam filters ensure that your mailbox stays clean. With SPF, DKIM, DNSSEC, etc., we also ensure the best deliverability

Access

Webmail as well as via IMAP, IMAPS, POP3, SSMTP, Managesieve. API usage for e.g. system mails is possible

Availability

99.9% annual average. Guaranteed by Service Level Agreement

Security

Data is stored exclusively on our servers in Frankfurt and is encrypted when not in use (Encryption at rest)

Public Sector Communication

S/MIME for Secure Email Communication

For secure communication with German public authorities, many organizations rely on S/MIME-signed and encrypted emails. Hostzero supports centralized setups where signing and encryption are handled server-side—employees continue to use their mailboxes as usual, without additional configuration or training.

Centralized Management

Certificates are managed centrally by administrators, with no effort required from end users.

Server-Side Signing

Automatic signing and encryption of all emails via a mail gateway.

Flexible Deployment

On-premises in your own data center or as a managed service in Frankfurt.

100% Open Source

Proven Technology Stack

We rely on well-established open-source components—transparent, auditable, and independent of proprietary vendors.

Postfix

Postfix

Proven mail transfer agent for reliable email delivery

Dovecot

Dovecot

Secure, high-performance IMAP/POP3 server

Rspamd

Rspamd

Modern spam filtering with machine learning support

ClamAV

ClamAV

Integrated antivirus scanning and content filtering

Frequently Asked Questions

What is the difference between transport encryption and S/MIME?
Transport encryption (e.g., TLS) secures the connection between mail servers. S/MIME protects the email content itself, regardless of the transport path, and additionally provides cryptographic signing to verify the sender’s authenticity.
How does S/MIME work without additional effort for employees?
The setup is implemented via a server-side mail gateway that automatically signs (and optionally encrypts) outgoing emails. Users do not need to install certificates or change any email client settings. All administrative effort is handled at the server or gateway level.
Is this BSI-compliant?
Our implementations follow the relevant BSI guidelines for secure email communication, particularly with regard to transport encryption, authentication, and organizational security measures. Actual compliance depends on the overall setup and the procedures in place.
What is the difference between a domain certificate and a personal certificate?
A domain (or organizational) certificate is issued to a company or domain and is typically used for centralized, server- or gateway-based scenarios. Personal certificates, on the other hand, are issued to individual users and are commonly used for user-specific S/MIME signatures. Which option is appropriate depends on the use case, technical requirements, and compatibility with the receiving systems.