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Novaz AuthenticatorGET

GMX 2FA: how to set up an authenticator app

By the Novaz team · Updated October 29, 2026
Novaz steps checked against version 1.0.5

On this page
  1. Turn on 2FA on GMX.com
  2. Turn on 2FA on GMX.net
  3. Email apps afterward
  4. When GMX asks for a code
  5. GMX has no backup codes: keep the secret key
  6. If GMX rejects your code
  7. Changing phones
  8. If you lose your authenticator
  9. Turning 2FA off
  10. Official GMX help

Two-factor authentication (2FA) on a GMX email account is optional. Once it's on, signing in on the web takes your password plus a 6-digit code from an authenticator app (GMX). There are no SMS sign-in codes and no backup codes, only a single secret key that GMX gives you as a PDF.

GMX runs two sites with separate help centers: gmx.com in English and gmx.net in German. Their setups differ: gmx.net also makes you approve it in the GMX App on your phone (GMX). Follow the steps for the site where you sign in. We use Authenticator App - Novaz on iPhone below, but any authenticator app works the same way.

How we checked this guide: the GMX steps come from GMX's own help centers and 2FA pages on gmx.com and gmx.net, linked below, which we read on October 21, 2026. The gmx.net pages are in German; the English in parentheses is our translation. We haven't tested the steps on a GMX account, so a label may differ slightly. The Novaz steps are checked against the app, version 1.0.5.

Turn on 2FA on GMX.com

Sign in at gmx.com in a browser, then follow GMX's help (GMX):

  1. Click Account at the top right, then Security Options on the left.
  2. Under Two-factor authentication, click Activate two-factor authentication, then Start setup now.
  3. Type your password and click Start now.
  4. Confirm your mobile number, or click Change if it's out of date. Click Request SMS, type the texted code and click Continue.
  5. A QR code appears. In Novaz, tap +, then Scan QR code. On the same iPhone, screenshot it and use Choose a photo. See scanning a QR code on the same iPhone.
  6. To type a key instead, click Copy code under the QR code. In Novaz, tap +, then Enter key manually, and paste it as the Setup key. See What is a 2FA setup key?
  7. Type the 6-digit code from Novaz and click Continue.
  8. Click Save your secret key, then check your details, click Next and Activate now.

GMX.com codes change every 30 seconds (GMX), which matches a key typed into Novaz. Some GMX.com pages start from the profile icon or My Account instead, so labels may differ.

Turn on 2FA on GMX.net

First, sign in to the current GMX App on your phone with notifications on, and check the postal address in your account (GMX). Then, at gmx.net:

  1. Click the icon with your initials, then Account verwalten (Manage account), then Login & Sicherheit (Login & security), and scroll to the bottom.
  2. Click Zwei-Faktor-Authentifizierung aktivieren (Activate two-factor authentication), Jetzt Einrichtung starten (Start setup now) and Ja, weiter (Yes, continue).
  3. Enter your password and click Jetzt starten (Start now).
  4. Tap the "GMX Sicherheit" notification on your phone and choose Ja, das war ich (Yes, that was me).
  5. Verify your mobile number with SMS anfordern (Request SMS), the texted code and Weiter (Next).
  6. Scan the QR code with Novaz as above, or use Code in die Zwischenablage kopieren (Copy code to clipboard) for the key, which GMX's scanning help calls Code kopieren (GMX).
  7. Type the Novaz code and click Weiter, then Geheimschlüssel sichern (PDF) (Save secret key), Weiter and Jetzt aktivieren (Activate now).

The gmx.net pages don't state the code interval, so scan the QR code when you can.

Email apps afterward

Sign in once more in the GMX Mail App and MailCheck. Outlook, Thunderbird and other POP3/IMAP programs need an application-specific password instead, shown only once, and POP3/IMAP access may need switching back on (GMX). On gmx.net the menu is App-Passwörter (für externe Apps) (App passwords) (GMX).

When GMX asks for a code

In a browser, at every sign-in. In the GMX Mail App, once (GMX). On gmx.net, ticking Für dieses Gerät merken (Remember for this device) stops the prompts on that browser. Unticking it later doesn't undo that; only deleting the browser's cookies does (GMX).

GMX has no backup codes: keep the secret key

The PDF holds a one-time key for password recovery, not for signing in. Using it switches 2FA off so you can set a new password (GMX). Even if you back up Novaz, print this key and store it away from the phone; it's what's left if the phone and your backup are both gone. More in 2FA backup codes.

If GMX rejects your code

GMX's help blames expired codes: enter the next one quickly (GMX). Also check your iPhone's clock: Settings > General > Date & Time > Set Automatically. Novaz shows a warning when the clock is 15 seconds or more off. See Authenticator code not working?

Changing phones

GMX lists a new smartphone as a use for the secret key (GMX). Simpler: while the old iPhone still works, turn 2FA off with a code from it (below) and run the setup again on the new one. With Novaz's iCloud backup or a backup file, you can instead restore your accounts on the new iPhone; see How to transfer your authenticator app to a new iPhone.

If you lose your authenticator

  1. Start password recovery: password.gmx.com for GMX.com, or assistent.gmx.net/recovery for GMX.net.
  2. Confirm it's you through your saved mobile number or contact email address.
  3. Enter the secret key. 2FA turns off, and you choose a new password (GMX).
  4. Sign in and set up 2FA again.

Lost the PDF too? Check your downloads folder first. GMX.com says customer support may be able to switch 2FA off, but only after a strict check that doesn't always succeed (GMX). On GMX.net, ask in the help chat (the speech-bubble icon on its help pages), and customer service can post access details to your saved address (GMX). If that address is wrong, GMX won't send a replacement (GMX). Neither says how long it takes. See Lost the phone with your authenticator app?

Turning 2FA off

In Security Options (gmx.com) or Login & Sicherheit (gmx.net), click Deactivate two-factor authentication or Zwei-Faktor-Authentifizierung deaktivieren. Enter your password and a Novaz code, then click Continue or Weiter (GMX, GMX). Afterward, open the GMX entry in Novaz and tap Remove account.

Official GMX help

GMX.com (English):

GMX.net (German):

More guides: Email