Does this work with any email provider?

With any provider that offers IMAP over SSL or TLS. That covers common web hosts such as IONOS, Strato and All-Inkl as well as your own mail servers. For Mailcow there is also a connector that synchronises users and aliases.

Are sent emails archived too?

Yes, as long as your mail client stores sent emails in the Sent folder on the server. EasyMailArchive reads all folders of the mailbox, including Sent. In most clients this is the default.

What is the difference to a BCC rule?

A BCC rule on the mail server captures every email at the moment it is sent or received. The IMAP import fetches what is in the mailbox, and new mail each time you click

Do I need an app password?

With providers that use two-factor sign-in, often yes. Create an app password in your provider's security settings and enter it instead of your normal password.

Archive an IMAP Mailbox (IONOS, Strato)

Many small businesses in Germany run their email at a web host: a few mailboxes at IONOS, Strato or All-Inkl, read with Outlook or Thunderbird. The retention duty under German commercial and tax law applies to them exactly as it does to large companies. The mailbox at the host is not an archive: emails can be deleted, and many plans have storage limits.

Legal basis

§ 257 HGB (German Commercial Code) requires merchants to keep received business letters (Handelsbriefe) and copies of sent ones.
§ 147 AO (German Fiscal Code) extends this to tax-relevant documents. The BFH (Federal Fiscal Court) held in order XI R 15/23 of 30 April 2025 that emails can be business letters.
GoBD, the tax authority's rules for electronic books and records, require such documents to be kept complete, unalterable and readable.

Retention periods: 6 years for business letters, 8 years for accounting vouchers including invoices (since 1 January 2025 under the Fourth Bureaucracy Relief Act, BEG IV), 10 years for books, annual financial statements and organisational documents. The 8-year period also applies to documents whose old 10-year period had not ended by 31 December 2024 (Art. 97 § 19a EGAO). Banks, insurers and investment firms follow one year later. The period starts at the end of the calendar year.

The problem

A hosted IMAP mailbox gives you no guarantee that mail stays complete. Users can delete or move emails without any log, a plan change can cut storage, and POP3 clients often remove mail from the server as soon as they download it. GoBD expects the opposite: every relevant email kept in its original form for the full period.

How the IMAP import works

EasyMailArchive connects to your mailbox over IMAP, reads all folders including Sent and stores each email in its original form. Emails that are already archived are not stored again. The import runs when you add the mailbox and each time you click Sync now. There is no automatic check for new mail today.

How to set it up with EasyMailArchive

Create an account. Sign up and try it for 30 days, no credit card.
Look up your host's IMAP details. Server name, usually imap.your-provider.de. EasyMailArchive connects over SSL on port 993.
Add the mailboxes. Under Admin > Integrations > IMAP mailboxes, click Add mailbox: server, username (the email address), password or app password. Check it with Test connection.
Assign them. Under Assign emails to, pick a user or group. This decides who owns the archived emails.
Add the mailbox. The import of existing mail starts right away. Fetch new mail later with Sync now. Older mail counts towards retention from its own date.
Set retention. For example 10 years for all mailboxes. Retention runs in whole years to 31 December of the year, and there is no delete function for single emails: mail is only deleted automatically when its period ends.

Details are in the help article on IMAP mailboxes at IONOS, Strato and others.

So that nothing is missing

Keep sent mail on the server. In Outlook or Thunderbird, check that the Sent folder lives on the server and not locally.
Use IMAP, not POP3. POP3 often deletes mail from the server once the client fetches it.
Add a BCC rule where possible. If you run your own server with Postfix or use Mailcow, also set up a BCC rule to your relay address ([email protected]). Then every email is captured at the moment it is sent or received. See the setup guide.

What you get

Every email is encrypted with AES-256 and a separate key per customer, in transit with TLS, in a data centre in Germany, with a separate database per customer. You can search across all mailboxes in the message body, sender, recipient, subject, date and plain-text attachments, and export as original EML or as PDF with SHA-256 checksums for your tax advisor or the tax audit. Every action is logged and the log exports as CSV.

See pricing or try it free for 30 days.

This article summarises the law in general terms and is not legal or tax advice.