Melanie2web: complete 2026 guide to the secure messaging system of the French ministries

Cerbère login, features, 2FA security, troubleshooting: everything you need to know about Melanie2web, the secure messaging service of the French ministries in 2026.

Melanie2web (also called Mél, Mélanie 2 or Mélanie 2 Web Din) is the professional email service used by more than 85,000 employees of the French ministries of Ecological Transition, Agriculture, Housing, Transports, the Sea, and Territorial Cohesion. Built on open-source software (Horde, Thunderbird) and hosted on public infrastructure under the aegis of DINUM, it is one of the pillars of the State’s digital sovereignty. Here is a complete and up-to-date guide for 2026: who it is for, how to log in via Cerbère, what its actual features are, and what to do in case of access issues.

What exactly is Melanie2web?

Melanie2web is the professional email platform deployed by the Ministry of Ecological Transition for its own employees and those of several partner ministries. Unlike Gmail or Outlook, it is not accessible to private individuals or private companies : only employees authorized by their administration have an account. The official access URL is mel.din.developpement-durable.gouv.fr. The service is managed by DINUM (Interministerial Digital Directorate), with the Ministry of Ecological Transition as the main hosting structure. A few figures show the scale of the deployment:

• More 85,000 mailboxes active
• Approximately 55,000 users in rich client mode (Thunderbird + Lightning + Apitech extensions)
• Approximately 44,000 users in web mode (PHP Horde / Kronolith interface)
• More 2,000 synchronized mobile devices via z-Push (ActiveSync) and CalDAV

The fully open-source architecture is a strategic choice: independence from proprietary vendors, control of the code by internal teams, and alignment with the French State’s digital sovereignty doctrine.

Who is Melanie2web for?

The service is reserved for employees of the following ministries and affiliated entities:

• Ministry of Ecological Transition and Territorial Cohesion (MTECT)
• Ministry ofAgriculture, Food and Food Sovereignty
• Ministry of Housing
• Ministry of Transports
• Ministry of Sea
• Departmental Directorates of Territories (DDT) and decentralized services
• Public institutions under the supervision of the above ministries
• Agricultural education (since October 2020, former FirstClass replaced)

Staff who do not fall within these scopes use another institutional email system (Diplomacy for Foreign Affairs, National Education for the MEN, Interior for the Ministry of the Interior, etc.).

How to log in to Melanie2web in 2026

The login relies on two pillars: the Cerbère username and two-factor authentication.

Step 1 — Check the prerequisites

• Have a valid staff account (created automatically by your administration)
• Have your Cerbère credentials (generally format [email protected])
• Use a recent browser: Firefox (reference), Chrome, Edge, or Safari
• If you are hors on the ministerial network: have an active VPN

Step 2 — Go to the interface

Open your browser and go to mel.din.developpement-durable.gouv.fr. You will arrive at the authentication page for the portail.

Step 3 — Authenticate with Cerbère

1. Enter your Cerbère username (your professional email address)
2. Enter your Cerbère password (different from your workstation password if configured)
3. Confirm using the second authentication factor (2FA): TOTP code sent to your professional phone or physical key
4. The webmail interface opens with your inbox

2FA is now mandatory in 2026, with no exceptions possible. The old access methods using only username + password are no longer permitted.

Connection via FranceConnect Agent

Depending on the ministries, authentication via FranceConnect Agent may be offered as an alternative. It does not replace Cerbère authentication for internal messaging but makes access to certain partner applications easier.

The actual features of Melanie2web

Email

The core of the service: sending, receiving, archiving. An interface equivalent to other professional webmail services with predefined folders (Inbox, Sent Items, Drafts, Archives) and the ability to create personal folders. Automatic filters are available to sort incoming messages.

Shared calendar

Kronolith module integrated into the portail. Allows the creation of personal and shared calendars, inviting other staff members to meetings, organizing team schedules, and synchronization with mobile devices via CalDAV.

Address book

Ministerial directory automatically synchronized with the Amande and Cerbère databases. You can also create your personal address books, import or export contacts in vCard format.

Task manager

Personal task lists or lists shared among staff members in the same department, with due dates, priorities, and progress status.

Instant messaging

Integrated chat module for quick exchanges between staff members, as an alternative to emails for non-critical topics.

Mélanissimo, France Transfert, iGusse: the complete ecosystem

Melanie2web is complemented by several sovereign services for needs that traditional email does not cover.

Mélanissimo and France Transfert

For large attachments that exceed the usual email limit (around 25 MB), two tools are available:

• Mélanissimo : internal service for sending large files between staff members
• France Transfert : sovereign interministerial service for exchanging large files between administrations and with external partners (French alternative to WeTransfer)

iGusse

Secure storage platform for documents shared between staff members and departments. Allows files to be pooled while complying with administrative confidentiality requirements.

Technical architecture and sovereignty choices

Melanie2web is based on an entirely open-source stack, making it one of the most advanced examples of sovereign public email in Europe.

Agents can also use Outlook or Apple Mail via IMAP/SMTP on configured workstations, with the same Cerbère credentials.

Security and Compliance

Several layers of protection are combined to ensure the confidentiality of exchanges:

• Cerbère authentication + mandatory 2FA in 2026
• Ministerial VPN required for any access outside the internal network
• TLS encryption on all web traffic
• Asymmetric cryptography (PKI / RSA) for sensitive exchanges
• Sovereign hosting on French public infrastructures
• GDPR Compliance native (French administration)
• Traceability and archiving of all exchanges (useful in the event of a dispute or administrative audit)
• Restricted access to authorized agents only by their administration

For defense-classified data or higher-level information, other systems (notably ISIS for sensitive data) take over. Melanie2web remains intended for routine professional exchanges with restricted distribution.

What should you do in case of a connection problem?

Here are the most frequent issues and their solutions.

Forgot your password?

Contact your administration’s support. Temporrary passwords now expire after 24 hours in 2026, which changes recovery practices.

Account locked after several attempts

Avoid re-entering an incorrect password several times. Beyond a certain number of failed attempts, the account is automatically locked. You must then alors go through your ministry’s DSI support for unlocking.

2FA authentication error

Check your phone’s time (TOTP codes are time-sensitive). If you have changed phones, contact support to regenerate your authentication key.

Access denied hors the network

Check that your ministerial VPN is active. Without a VPN, access to Melanie2web is filtered by certain security policies.

Main support number

The Ministry for the Ecological Transition, the supervisory body of Melanie2web, can be reached at +33 1 40 81 21 22 during business hours. For urgent issues outside these horours, your local ministerial IT department remains the primary point of contact.

FAQ — Melanie2web

Who can use Melanie2web?

Only staff of the ministries of the Ecological Transition, Agriculture, Housing, Transporrt, the Sea, and Territorial Cohesion, as well as staff of the Departmental Directorates of Territories and agricultural education. The service is not accessible to private individuals or private companies.

How to create a Melanie2web account?

You cannot create it yourself. The account is generated automatically by your administration beforre you take up your position, via the Amande and Cerbère directories. If you are a new staff member and do not yet have credentials, contact your HR department or your ministerial IT department.

What is the official access URL for Melanie2web?

mel.din.developpement-durable.gouv.fr. This is the only official address. Be wary of sites that imitate the interface: they may be phishing attempts.

What is Cerbère and what is it used for?

Cerbère is the central authentication directory for the MTE ministries and partners. Your Cerbère identifier (in the forrm [email protected]) gives you access to Melanie2web as well as many other internal ministerial applications via a single sign-on system.

Is 2FA really mandatory in 2026?

Yes. Two-factor authentication is now mandatory for all staff, without exception or waiver. This requirement accompanies the overall strengthening of security policies in the civil service.

Can Melanie2web be used from a personal smartphone?

Synchronization is technically possible via z-Push or IMAP/SMTP settings, but it requires the authorrization of your IT department and compliance with a security policy (VPN, mobile device management). In practice, only professional devices managed by the administration are authorrized in the majorrity of cases.

How to send a file that is too large via Melanie2web?

For attachments that exceed the email size limit, use Mélanissimo (internal) or France Transfert (interministerial and with external partners). These two sovereign services are integrated into the ministerial ecosystem.

What should I do if I can no longer log in to Melanie2web?

First check your credentials, your VPN if you are accessing remotely, and your 2FA code. If the problem persists, contact your local ministerial IT department or central supporrt at +33 1 40 81 21 22 during business hours.

Are my old emails backed up?

Yes. All exchanges are tracked and archived in accorrdance with administrative obligations. The server keeps the historry of the mailbox, making it possible to retrieve old exchanges if necessary (dispute, audit, handover to a successor).