# mail.com MailCheck

> Mail notifier for multiple email accounts.

Canonical page: [https://chrome-stats.com/d/mailcom-mailcheck](https://chrome-stats.com/d/mailcom-mailcheck)

## Overview

- **ID:** `mailcom-mailcheck`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** 1&1 Mail & Media GmbH
- **Category:** appearance,alerts-updates
- **Daily users:** 1,214
- **Weekly downloads:** 34
- **Rating:** 2.70 / 5 (82 ratings)
- **Version:** 8.0.20
- **Last updated:** 2026-06-25
- **First published:** 2012-12-03
- **Size:** 2.28 MB
- **Data as of:** 2026-09-14
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/mailcom-mailcheck/)
- **Website:** [https://support.mail.com/mailcheck/](https://support.mail.com/mailcheck/)
- **Privacy policy:** [https://addons.mozilla.org/firefox/addon/mailcom-mailcheck/privacy/](https://addons.mozilla.org/firefox/addon/mailcom-mailcheck/privacy/)

## Description

mail.com MailCheck is a powerful Chrome extension that acts as a mail notifier for your multiple email accounts. It delivers email notifications directly in your browser and on your desktop, ensuring you never miss important messages.

With just one click, you can read and write emails seamlessly within a single tool. It supports popular email providers such as mail.com, GMX, and WEB.DE, and now includes notifications for new and unread emails in your Gmail and Outlook accounts. Security is a top priority, featuring encrypted SSL connections and robust password protection to keep your information safe.

## Rankings

- #2,997 — Overall
- #77 — Alerts & Updates
- #15 — mail
- #51 — email
- #54 — hotmail
- #57 — password-protected

## Permissions and access

### Permissions

- `activeTab`
- `tabs`
- `storage`
- `management`
- `notifications`
- `contextMenus`
- `identity`
- `search`
- `https://*.mail.com/*`

### Content script matches

- `*.web.de`
- `*.gmx.net`
- `*.gmx.de`
- `*.gmx.ch`
- `*.gmx.at`
- `*.gmx.com`
- `*.mail.com`
- `*.1und1.de`
- `*.1and1.com`
- `search.mail.com`
- `dl.web.de`
- `dl.gmx.net`
- `dl.gmx.com`
- `dl.mail.com`
- `dl.1und1.de`
- `www.adsensecustomsearchads.com`
- `1und1.de`
- `www.1und1.de`
- `gmx.net`
- `www.gmx.net`
- `gmx.com`
- `www.gmx.com`
- `mail.com`
- `www.mail.com`
- `web.de`
- `www.web.de`
- `login.live.com`

## Safety

- **Risk impact:** Very high risk impact
- **Risk likelihood:** High risk likelihood

### Analysis details

- Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern.
- This extension has low user count. Unpopular extensions may not be stable or safe.

> Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing).

## Review summary

Recurring issues across reviews show the Firefox version of mail.com MailCheck is unreliable: many users cannot log in, experience Firefox-specific compatibility problems, and cannot add accounts, with some privacy concerns raised about data telemetry. The lack of consistent developer support is also noted.

### Cons

- Frequent login failures on Firefox: login button inactive or sign-in process hangs.
- Firefox compatibility issues: reports that the extension works in Chrome but not in Firefox, with compatibility warnings.
- Account setup flow is broken in Firefox: users cannot add new accounts and password input may be missing or blocked.
- Privacy concerns: reports of telemetry and data collection/sharing.

## Similar extensions and apps

- [WEB.DE MailCheck for Firefox](https://chrome-stats.com/d/webde-mailcheck) — 21,787 users, 3.03 / 5
- [GMX MailCheck for Firefox](https://chrome-stats.com/d/gmx-mailcheck) — 17,540 users, 2.84 / 5
- [Email Notifier](https://chrome-stats.com/d/email-notifier) — 367 users, 3.37 / 5
- [GMX.com MailCheck for USA, CA, UK, FR and ES](https://chrome-stats.com/d/gmx-com-mailcheck) — 1,831 users, 3.71 / 5
- [X-notifier (for Gmail,Hotmail,Yahoo,AOL ...)](https://chrome-stats.com/d/xnotifier) — 6,147 users, 2.89 / 5
- [Mail Checker for Proton Mail](https://chrome-stats.com/d/mail-checker-for-proton-mail) — 13 users, 5.00 / 5
- [GMX Mail Checker](https://chrome-stats.com/d/gmx-mail-checker) — 19 users
- [1&1 MailCheck](https://chrome-stats.com/d/1und1-mailcheck) — 802 users, 1.67 / 5
- [Mail Notifier for Outlook™](https://chrome-stats.com/d/mail-notifier-for-outlook) — 297 users, 3.71 / 5
- [Badge Checker for Gmail™](https://chrome-stats.com/d/badge-checker-for-gmail) — 22 users, 5.00 / 5
- [Checker Mail.ru](https://chrome-stats.com/d/checker-mail-ru) — 70 users, 5.00 / 5
- [WriterAccess Mail Check](https://chrome-stats.com/d/writeraccess-mail-check)

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Source: [Chrome-Stats](https://chrome-stats.com/d/mailcom-mailcheck)