Data sovereignty on site with REDDOXX MailDepot
Email Archiving with a Legally Compliant Software Solution
REDDOXX MailDepot is an email archiving software solution for companies with 10 to 15,000 mailboxes. The software runs as a virtual appliance on-premises on your own infrastructure, automatically archives emails in a tamper-proof manner, and complies with GoBD, GDPR, and HGB—all without relying on the cloud.
Legally Compliant Email Archiving Software with REDDOXX MailDepot
REDDOXX MailDepot automatically archives all incoming and outgoing emails in their entirety and in an unalterable format. The solution captures every message before it reaches the inbox and stores it in an audit-proof manner. Whether it’s GoBD, GDPR, or the German Commercial Code (HGB), MailDepot meets all legal requirements for business email archiving while also making email management within the company faster and easier.
All emails are automatically archived in an audit-proof manner. Even if users accidentally delete emails from their inboxes, they remain fully preserved in the archive.
By automatically swapping out old messages, you reduce the storage requirements and system load on your email servers – this increases performance and stability.
Thanks to the powerful full-text search, you can find emails and any attachments (e.g. PDF, Office documents such as Word or Excel) within seconds – even in large databases.
Compression, deduplication and efficient storage in the archive save you expensive storage space and keep mailboxes lean.
No more scattered, insecure and difficult-to-manage PST files. With MailDepot, all messages are archived centrally and can be accessed at any time.
MailDepot ensures legally compliant archiving and fulfills all relevant requirements for storage, data protection and traceability.
What features does the email archiving software offer?
MailDepot offers everything that companies need for efficient, secure and legally compliant email archiving and makes working with emails noticeably easier. From full-text search to seamless integration into existing IT systems: MailDepot is a powerful, modular solution that grows with your requirements.
Works with any mail server – even if you change it from time to time
Our email archiving software works independently of the mail server used. Whether it’s Microsoft Exchange, Microsoft 365, Zimbra, Kerio Connect, Postfix, GroupWise, or HCL Notes (Lotus Notes)— integration is straightforward and flexible. Even hybrid Microsoft 365 environments can be seamlessly integrated via SMTP journaling.
And best of all: If you switch mail servers, you can continue to archive your emails. For example, thanks to industry standards, you can easily restore an email archived in Lotus Notes on a Microsoft Exchange Server.
Supports any storage: whether NAS, SAN or VirtualDisc
With REDDOXX MailDepot, you are completely flexible in your choice of storage. Whether local NAS, high-performance SAN or a virtual hard disk in your virtual environment – the system adapts seamlessly to your existing IT infrastructure. This allows you to make optimum use of existing storage capacities and save costs.
And the best thing is that you don’t have to plan the storage for the next 10 years today, but can expand it at any time during operation.
Full text search even in PDF files and other attachments: find 10-year-old emails in 5 seconds
Thanks to intelligent full-text indexing, MailDepot not only searches subject lines and email content, but also text-based attachments such as PDFs, Word or Excel documents. Even with large databases, you can find any email you are looking for within seconds – quickly, precisely and conveniently.
And best of all: You can find emails from years ago in a matter of seconds. Even messages from 10 years ago and their attachments are just a mouse click away—even if the employees are no longer with the company.
What Sets Our Email Archiving Software Apart
With MailDepot, you’re not just investing in a powerful email archiving program—you’re investing in a system that grows with your needs. From compliance and storage optimization to easy management and role-based access permissions, MailDepot offers everything you need.
Whether through a web browser, smartphone app, Windows app, or Outlook plugin—you and your employees have fast and convenient access to all archived emails at any time.
Import existing databases and delete legacy data. Thanks to flexible export options, you remain independent and avoid artificial vendor lock-ins.
Define custom access rights and, for example, grant access to archived emails from former employees—in a legally compliant and traceable manner.
Comply with data protection requirements such as the GDPR. Delete emails on request – for example rejected applications – and always remain compliant.
MailDepot grows with your business. Add-ons such as built-in spam protection or email encryption software can be seamlessly integrated.
Manage MailDepot conveniently through a modern web interface—including easy update and maintenance features for administration.
On-Premises Email Archiving:
Full data sovereignty on your infrastructure
REDDOXX MailDepot runs exclusively on your own infrastructure. All archived emails remain in your data center, with no external access and no dependence on third-party providers. MailDepot is offered as a perpetual user license, with no monthly subscription fees and no vendor lock-in: Thanks to open standards and flexible export options, you retain full control over your archived data at all times.
MailDepot also ensures transparency internally. Every instance of access to archived emails is logged in a comprehensive audit trail. You can track at any time who viewed or exported which message and when, which ensures security during both internal reviews and external audits.
Who is our email archiving solution best suited for?
REDDOXX MailDepot is intentionally designed to be flexible: The solution can be used efficiently in both small businesses with just a few mailboxes and large, distributed environments with thousands of users. The solution is easily installed as a virtual appliance in your existing environment and is up and running in just a few steps —without any major setup effort. A full trial license is available free of charge and can typically be put into production within 2 to 4 hours.
Small businesses benefit from a straightforward, legally compliant archiving solution that requires no additional infrastructure and no ongoing maintenance. Large companies receive a powerful system with role-based access and a comprehensive compliance framework —even across multiple locations or domains.
MailDepot is designed for companies that want to keep their email data on their own infrastructure. For companies that prefer a cloud-based solution, REDDOXX offers cloud-based email archiving —an alternative specifically optimized for Microsoft 365 environments.
As email archiving software for small businesses, MailDepot can be quickly integrated into existing systems and immediately provides legally compliant archiving—without the need for complex infrastructure.
Increasing email volume, limited IT resources? With MailDepot, you can relieve the load on your mail server, reduce storage requirements and keep an overview at all times with the full-text search.
Multiple locations, many mailboxes, clear compliance requirements? MailDepot is scalable, multi-domain capable and meets the highest data protection and archiving requirements.
Ideal for law firms, tax offices, medical facilities, educational or administrative institutions – wherever long-term archiving of important data is required.
How the REDDOXX MailDepot Email Archiving Software Works
MailDepot is quick to set up and integrates seamlessly into your existing IT environment.
The email archiving software then runs automatically in the background, allowing your employees to focus on what matters most: working productively with email.
1. installation and setup
MailDepot is integrated into your existing IT infrastructure as a virtual appliance. It is installed on your preferred virtualization platform – e.g. VMware, Hyper-V, XEN, KVM, Proxmox or other hypervisors.
After installation, the appliance undergoes basic configuration, for example with the connection to your Active Directory (LDAP) to automatically synchronize users, groups and e-mail addresses.
As soon as the environment is set up, you can activate archiving, define rules and connect the first mailboxes.
2. automatic archiving
Once set up, MailDepot automatically begins archiving all incoming and outgoing emails. Internal emails can also be included if desired.
Archiving is performed independently of the mail server used and ensures that all messages are stored in their entirety, in an unalterable and audit-proof manner.
Through journaling, SMTP forwarding (for example, via Postfix), integration as a central gateway for SMTP traffic, or POP3 access, even complex mail flows can be fully tracked.
Data is always captured before a message reaches the inbox. This ensures that even deleted or moved emails are fully preserved in the archive. A cryptographic hash value for each email makes it possible to detect any subsequent changes at any time.
3. compliance and discharge
MailDepot reliably ensures compliance with all legal requirements in the background – including the GoBD, GDPR and other national and industry-specific requirements.
MailDepot supports compliance with the statutory retention periods of 6 years for business correspondence (Section 257 of the German Commercial Code (HGB)) and 10 years for tax-related documents such as invoices (Section 147 of the German Fiscal Code (AO)), including the archiving of electronic invoices. All access to archived emails is logged in an audit trail, which ensures complete traceability during internal reviews and external audits.
At the same time, the solution noticeably reduces the load on your IT structure: archived emails are outsourced from the mail server and deduplicated, which saves storage space and improves performance.
Insecure and difficult to maintain PST files are also a thing of the past – all emails are stored centrally, securely and searchable.
4. find emails in seconds
As soon as emails are archived, they are available via the powerful full-text search – including all text-based attachments (e.g. PDF, Word, Excel).
The search is lightning-fast – even with large databases of several terabytes – and can be used via the web browser, the Outlook plug-in, a Windows client or the smartphone app.
This way, your employees can find what they need in a matter of seconds—whether it’s 10 days or 10 years old.
The REDDOXX Appliance is a virtual machine and can be installed under almost any hypervisor. VMware, Hyper-V, Citrix XEN, KVM, Proxmox, Nutanix AHV or Virtual Box are supported, among others.
If you don’t have your own virtual environment or don’t want to use email archiving locally, we recommend our Cloud Archive – 100% in German data centers, of course.
No. MailDepot works independently of the mail server used and integrates seamlessly into your existing environment – whether Exchange, Microsoft 365, Postfix, Lotus Notes or other systems.
With on-premises archiving, all emails remain on your own infrastructure. There is no external access to data and no dependence on a cloud provider. This complete control over data is often a key requirement, particularly in regulated industries such as tax and legal consulting or healthcare. But on-premises solutions also offer the greatest possible autonomy for all other companies that wish to maintain control over their data.
The virtual appliance is usually installed and configured within 2-4 hours. After the basic configuration, you can start archiving immediately. For more complex environments, we recommend scheduling 4-8 hours.
Yes, MailDepot meets all the requirements for legally compliant email archiving: immutability, traceability, retention obligations and data protection-compliant deletion.
Business emails are subject to statutory retention periods in Germany. A 6-year retention period applies to business correspondence (Section 257 of the German Commercial Code (HGB)), and a 10-year retention period applies to tax-related documents such as invoices and receipts (Section 147 of the German Fiscal Code (AO), GoBD). MailDepot helps you comply with these retention periods while also enabling the GDPR-compliant deletion of personal data once the respective retention obligation has expired.
Archived emails from former employees are retained – even if you delete these users in the Active Directory – and can be viewed by authorized persons – with documented access control, of course.
Yes, MailDepot supports a wide range of import options, including importing existing PST files or importing the Exchange database. This allows you to consolidate your email history and create a standardized, central archive structure.
No. You are free to choose where the archive data is stored – whether NAS, SAN or virtual environment. And best of all: the storage can be expanded at any time during operation if required.
Yes, this is possible – in compliance with legal requirements. The integrated compliance framework can be used to define deletion guidelines, e.g. for the timely removal of personal data (such as rejected applications). On request, individual emails or entire data areas can be removed in compliance with the GDPR – documented and traceable.
No problem. REDDOXX MailDepot archives independently of the mail server used. This means that even if you completely change your email infrastructure – e.g. from Lotus Notes to Microsoft Exchange or to the cloud – the existing archive is completely retained and remains accessible. Once an email has been archived, it can be restored to any mail system.
A backup is used for recovery in an emergency, e.g. in the event of system failures. Archiving, on the other hand, stores emails permanently, completely and in an audit-proof manner – regardless of the mailbox. Both complement each other, but fulfill different purposes.
Audit-proof archiving ensures that emails can be retrieved and displayed with their content remaining completely identical even years after archiving. It must be possible to verify that the data remains in its original, unaltered state at all times. The data must not be altered—either intentionally or accidentally—during the specified archiving period.
According to many generally recognized definitions, audit-proof archive systems meet the following requirements (among others):
Archived information…
- … are unchangeable
- … can be found again
- … the archiving is traceable
- … the data is protected against forgery and manipulation
Important to know: Audit-proof archiving is not only the result of certain technical features. Rather, it also includes operational processes, for example, which ensure that all relevant data is recorded completely and without gaps.
Every email archived in MailDepot is assigned a cryptographic hash value upon receipt. This makes any subsequent modification technically detectable and permanently ensures the integrity of every archived message. Archiving itself takes place automatically via journaling or an SMTP gateway before a message reaches the recipient’s mailbox. Even if employees delete or move emails from their mailbox, the originals remain fully preserved in the archive.
When it comes to the long-term storage of email correspondence, it is particularly crucial for companies to implement a legally compliant email archiving system. This is because it is by no means sufficient to simply back up emails from time to time or to store them on a backup medium without taking any further precautions.
In many respects, emails containing business-related content are equivalent to traditional, paper-based business letters and documents. The validity of a quote, an invoice, or a contractual agreement is not affected by whether it is sent by regular mail, fax, or email. As the volume of business emails continues to rise and more and more transactions are conducted this way, there is a growing need to address the issue of legally compliant email archiving in a thorough and sustainable manner.
How can this be implemented in practice? To archive emails securely, many factors must be taken into account. A number of regulations and deadlines stem directly from the fact that business emails are treated the same as corresponding business letters. This applies, for example, to the retention periods for documents relevant under tax law, such as invoices or receipts. Additional criteria for legally compliant email archiving can be derived from the various guidelines for handling computer-based data.
The ordinances, laws, and regulations that companies must comply with include, among others, the German Commercial Code (HGB), the so-called “Principles for the Proper Maintenance and Retention of Books, Records, and Documents in Electronic Form, as well as for Data Access” (GoBD for short), and the German Fiscal Code (abbreviated as AO). Also important for legally compliant email archiving until the end of 2014 were the Principles of Proper Computer-Based Accounting Systems (GoBS), a collection of regulations that were primarily relevant to accounting for tax purposes and dealt with document management and the design of archiving systems. These regulations have been incorporated into the new GoBD.
Overall, it is clear that companies cannot rely on a single, specific guideline when setting up their mail archiving, but must take the applicable requirements from a plethora of regulations and implement them in the best possible way.
Occasionally, interested parties approach us who would like to implement email archiving using the “stubbing” method. With this method, only the header information of the emails remains in the local email client. This includes data such as the subject line, the sender, or the date of the message. The actual content—such as the body of the email or any attachments—is stored on a separate storage system.
One of the reasons behind stubbing is usually the desire to reduce the memory load on local systems. However, in our view, there are many aspects that speak against such an approach. This is because the supposed advantages generally do not stand up to critical scrutiny or even turn out to be the opposite. This is because stubbing often leads to a drop in performance, especially when searching for and restoring emails, as countless database entries are inevitably created due to the necessary links between the header and body information of the messages. In addition, the legal security of the archive can be jeopardized as the emails are not archived in their original, unaltered state due to the splitting.
