Is WEB.DE MailCheck safe?

Low risk

Shows browser notifications for new email across configured mailboxes.

This extension lets you monitor email accounts in Chrome, open the mailbox, preview messages, delete emails with one click, and customize the notification sound. During first setup it transmits the email address and password in encrypted form, then stores the email address locally and does not store the password. It also collects non-personal technical data such as version number, country, brand, and timestamp when the browser starts.

Part of this rating comes from analysis signals we haven't published as detailed findings yet.

1&1 Mail & Media GmbHv8.0.5.0Chrome Web Store
15Risk
Who publishes it

1&1 Mail & Media - 1 other listing from the same operator, none carrying a finding

What this publisher told the store about itself, and the other listings that told it the same thing.

Publisher
1&1 Mail & Media GmbH
Declared legal entity
1&1 Mail & Media
Registered address
Elgendorfer Str. 57, Montabaur 56410, DE
Registered contact
1&1 Mail & Media GmbH
Website
hilfe.web.de/mailcheck/googlechrome.html

Same store account

1 other listing published from this account, 40k+ users between them, none of them carrying a finding.

MailCheck40k+Low

Shared hosts - 27 hostnames

Hostnames hardcoded in this extension that few other listings call. That can mean one operator behind both, and it can equally mean a small shared vendor, so it is context rather than a conclusion. Hosts that many listings call are left out: they are services, not connections.

mail.com
Also called by 2 other listings, including Ready Mail New Tab
gmx.net
Also called by 3 other listings, including Fenerbahçe SK Anasayfa, beşiktaş-jk-anasayfa
tgw.web.de
Also called by 3 other listings, including WEB.DE MailCheck for Firefox
go.web.de
Also called by 4 other listings, including WEB.DE MailCheck for Firefox
oauth2.gmx.net
Also called by 4 other listings
adsensecustomsearchads.com
Also called by 5 other listings, including WEB.DE MailCheck for Firefox, GMX MailCheck for Firefox, mail.com MailCheck
oauth2.web.de
Also called by 5 other listings
suche.web.de
Also called by 5 other listings, including WEB.DE MailCheck for Firefox, GMX MailCheck for Firefox, mail.com MailCheck
lts.1und1.de
Also called by 6 other listings, including GMX MailCheck for Firefox
uas2.uilogin.de
Also called by 6 other listings, including GMX MailCheck for Firefox
dl.gmx.net
Also called by 7 other listings
dl.web.de
Also called by 7 other listings
bs.navigator.gmx.net
Also called by 8 other listings
img.ui-portal.de
Also called by 8 other listings, including mail.com MailCheck
1und1.de
Also called by 9 other listings
bs.navigator.web.de
Also called by 9 other listings
dl.1und1.de
Also called by 9 other listings
dl.gmx.com
Also called by 9 other listings
dl.mail.com
Also called by 9 other listings
hsp.gmx.com
Also called by 9 other listings, including mail.com MailCheck
hsp.gmx.net
Also called by 9 other listings
hsp.mail.com
Also called by 9 other listings
hsp.web.de
Also called by 9 other listings
netid.de
Also called by 9 other listings
oauth2.gmx.com
Also called by 9 other listings
oauth2.mail.com
Also called by 9 other listings
wikipedia.de
Also called by 9 other listings

AI-generated. Findings may contain errors. Those marked Verified have been manually reviewed.

Publishers can request a review.

What it can do

Permissions this extension asks for, as declared in version 8.0.5.0. Asking for a permission is not a finding on its own - it is what the extension can do if it chooses to.

  • Read and change your data on web.de

    https://*.web.de/*

  • Read and change your data on gmx.net

    https://*.gmx.net/*

  • Read and change your data on 1und1.de

    https://*.1und1.de/*

  • Read and change your data on uilogin.de

    https://*.uilogin.de/*

  • Read and change your data on mail.com

    https://*.mail.com/*

  • Read and change your data on accounts.google.com

    https://accounts.google.com/*

  • Read and change your data on www.googleapis.com

    https://www.googleapis.com/*

  • Read and change your data on mail.google.com

    https://mail.google.com/*

  • Read and change your data on live.com

    https://*.live.com/*

  • Read and change your data on localhost

    *://localhost/*

  • Act on the current tab, but only after you click the extension

    activeTab

  • Schedule its own background tasks

    alarms

  • See the address and title of every tab you have open

    tabs

  • Run its own code inside the pages you visit

    scripting

  • Store data in your browser

    storage

  • Show you desktop notifications

    notifications

  • Run hidden pages in the background

    offscreen

  • Add items to the right-click menu

    contextMenus

  • Sign you in with your Google account

    identity

Where it sends data

Destinations our analysis observed MailCheck contacting. Sending data somewhere is not a finding on its own - an extension that syncs your settings has to talk to its own server - but it is where your data can go, and who else it goes to.

  • WEB.DE

    MailCheck sends data to WEB.DE. No other extension we have analysed sends data here.

Updated 30 September 2026jaogepninmlbinccpbiakcgiolijlllo