Beginner-friendly guide

Set up your firm mailbox Step by step to LexA

How your existing addresses name@kanzlei-name.de can run on Microsoft 365 or Google Workspace and then connect securely to LexA – explained in plain language, no IT knowledge required.

Important: your domain stays registered with IONOS or STRATO. Only a few email records (DNS) change – your domain contract, your invoice and any website remain untouched.
Introduction

Why move? The benefits

A plain IONOS or STRATO mailbox is fine for receiving mail, but for a law firm using LexA it has drawbacks: no modern sign-in (no OAuth) – LexA would have to store your password; no two-factor protection of the connection; and no modern features such as reliable sync or server-side search. Microsoft 365 and Google Workspace solve this – and for a law firm they are also the better choice in terms of data protection.

Recommended

Microsoft 365

Our recommendation

  • Most secure LexA connection: modern sign-in (OAuth). LexA only receives a revocable access token – your password never leaves your premises.
  • Data protection for professional-secrecy holders: Microsoft EU Data Boundary (data processing in the EU), expansion of in-Germany processing in 2026, data processing agreement (AVV). A solid basis for Art. 28 and Art. 44 ff. GDPR and § 203 StGB – the case-by-case legal assessment is made by your counsel.
  • Familiar tools: Outlook, Word, Excel – including desktop Office in the Business Standard plan, ideal for legal briefs.
  • Convenient via SDN/LexA: we can handle licence, setup and billing for you – one point of contact.
Alternative

Google Workspace

The secure alternative

  • Equally modern, secure LexA connection via OAuth (Gmail).
  • Lean, very easy to use: Gmail, Calendar, Drive and Meet.
  • Suited to firms already working in the Google ecosystem. Note: check the data region and the EU commitments for professional-secrecy holders with your legal counsel.

Both providers are priced closely. We recommend Microsoft 365 (Business Standard) – for desktop Office, the mature data-protection framework and the all-round support from SDN/LexA. If you already work with Google, Google Workspace is just as secure. We are happy to share concrete licence prices in a conversation.

Overview

The path in three stages

You choose one of the two paths. Both end the same way – at the step “Connect the mailbox to LexA”.

  1. 1

    Domain stays with IONOS / STRATO

    Only a few DNS records are adjusted. Registration, contract and invoice remain unchanged.

  2. 2

    Mailbox moves

    Your addresses name@kanzlei-name.de will run on Microsoft 365 or Google Workspace.

  3. 3

    Connect the mailbox to LexA

    Via modern sign-in (OAuth) – LexA only receives a revocable access token, never your password.

Which path suits you?

You already use Word/Outlook or want desktop Office and all-round support → Microsoft 365. You already work with Gmail/Google → Google Workspace. When in doubt: Microsoft 365.

Create account

Create the account yourself at the provider

You can create the account directly with the provider – with a free trial, then purchase. The links below lead to the official sign-up. With the account you get not only the mailbox but a whole package of additional services.

Recommended

Microsoft 365

Try / buy Microsoft 365(opens at Microsoft)

Included services

  • Business email (Exchange/Outlook)
  • Teams (chat & video conferencing)
  • OneDrive (1 TB cloud storage)
  • SharePoint
  • Word, Excel, PowerPoint, Outlook (web & mobile; in the Business Standard plan also as desktop apps)
  • OneNote, Loop, Clipchamp
  • Bookings, Planner, Forms
Alternative

Google Workspace

Try Google Workspace(opens at Google)View plans(opens at Google)

Included services

  • Business email (Gmail)
  • Calendar
  • Meet (video conferencing)
  • Chat
  • Drive (cloud storage)
  • Docs, Sheets, Slides
  • Forms, Sites
  • Gemini (AI assistant)
  • Plus Keep, Tasks, Vids, NotebookLM, AppSheet
For a law firm we recommend a business plan (Microsoft 365 Business or Google Workspace Business) with your own domain kanzlei-name.de – not the free personal account. Provider plans and prices may change; the provider's own page is authoritative. On request, SDN/LexA will handle the setup for you. Get in touch
Step by step

Two setup manuals

Choose one path. Both manuals end the same way – at the step “Connect the mailbox to LexA”. Follow either Microsoft 365 (recommended) or Google Workspace.

Video tutorialVideo tutorial coming soonA step-by-step video tutorial is in the works. Until then, the guide below walks you through every step.

Step 1: Set up the Microsoft 365 mailbox for the firm

  1. Choose a Microsoft 365 plan (recommendation: Business Standard with desktop Office; Business Basic is enough if Office is already in place). Convenient: purchase via SDN/LexA – we set it up and bill it.
  2. Sign in to the Microsoft 365 admin center (admin.microsoft.com).
  3. Under Users → Active users, create a user account for every lawyer and every staff member.
Screenshot coming soon
Plan selection, sign-in to the Microsoft 365 admin center and creating the user accounts.

Step 2: Add and verify your own domain

  1. In the admin center: Settings → Domains → Add domain.
  2. Enter kanzlei-name.de and click “Use”.
  3. Microsoft shows a TXT record for confirmation (form MS=ms…). Note the value.
  4. Enter this TXT record in your registrar’s DNS – see step 3 (tab “DNS at IONOS” or “DNS at STRATO”).
  5. Back in the admin center, click “Verify”. Confirmation usually takes a few minutes.
Screenshot coming soon
The “Add domain” dialog and the TXT verification record shown by Microsoft.

Step 3: Change the DNS records at your provider

Choose your registrar:

  1. 1Sign in to IONOS → Domains & SSL → kanzlei-name.de → DNS.
  2. 2TXT (verification): record with the MS=ms… value from step 2 (host/name @).
  3. 3MX: remove the existing IONOS MX records, add a new MX → kanzlei-name-de.mail.protection.outlook.com, priority 0.
  4. 4SPF (TXT): v=spf1 include:spf.protection.outlook.com -all.
  5. 5DKIM: two CNAME records selector1._domainkey and selector2._domainkey to the targets shown by Microsoft.
  6. 6Autodiscover (CNAME): autodiscover → autodiscover.outlook.com.
  7. 7DMARC (TXT, recommended): host _dmarc, value v=DMARC1; p=quarantine; rua=mailto:postmaster@kanzlei-name.de.
  8. 8Save.
Screenshot coming soon
The IONOS DNS panel with the new MX, SPF, DKIM and Autodiscover records.

Step 4: Bring across existing emails

optional

If you want to keep your previous inbox: start the IMAP migration before switching the MX (admin center → Exchange → Migration, source imap.ionos.de or imap.strato.de) so no inbox is kept twice. Order: verify domain → create mailboxes → migrate → switch MX → decommission the old mailbox after a grace period. If unsure, SDN/LexA can assist.

Screenshot coming soon
IMAP migration in the Microsoft 365 admin center.

Step 5: Connect the mailbox to LexA

  1. Sign in to LexA (app.lexatech.de) → Settings → Email / Mailboxes.
  2. Choose “Connect mailbox” → Microsoft 365.
  3. Get redirected to the Microsoft sign-in and sign in with name@kanzlei-name.de.
  4. Confirm access for the LexA app (consent to the lexa-mail app published by SDN).
  5. Done: the mailbox shows as connected.
Screenshot coming soon
The LexA “Email / Mailboxes” settings and the Microsoft consent dialog.
LexA never stores your email password, only a revocable access token.
Appendix

Prefer to stay on your IONOS/STRATO mailbox?

In future, LexA can also connect an IONOS or STRATO mailbox directly via IMAP/SMTP (email address + password). This option is less secure (no modern OAuth, the password is stored at LexA), offers fewer features and does not work for Microsoft 365 mailboxes. We recommend the path via Microsoft 365 or Google Workspace. Get in touch if the direct connection is necessary for you.

We’ll set it up for you

You’d rather not do the move yourself? SDN/LexA handles the licence, setup, DNS changeover and the LexA connection – all from one source. We share concrete licence prices in a conversation.

Get in touchBook a demo