Mélanie2Web is the ministerial messaging system used daily by tens of thousands of public service agents. Behind this web interface lies a larger ecosystem, undergoing transformation towards the Digital Office (Bnum), which changes how one accesses emails, calendars, and collaborative tools. Understanding these developments from the first login helps avoid the most common blockages.
Two-Factor Authentication for Remote Work on Mélanie2Web
Since the 2025-2026 period, two-factor authentication is mandatory for remote work: the Cerbère username/password combination is no longer sufficient when the agent connects outside the ministerial network.
A temporary code or a certificate complements the usual password. In case of loss of the second factor, the recovery procedure systematically goes through DIN support, which can take several business days.
Before getting stuck on a Monday morning while working remotely, it is better to anticipate by consulting the resources provided on innovotech.fr to correctly configure this second factor from the first connection.
- Check that the phone number associated with the Cerbère account is up to date, as the temporary code is sent there by default.
- Test the connection outside the ministerial network at least once before the first actual remote workday.
- Note the contact procedure for DIN support (accessible from the ministerial intranet) so you don’t have to search for it in an emergency.
Migration to the Digital Office Bnum: What Changes for Mel Messaging
Mélanie2Web is no longer an isolated webmail. The platform is gradually migrating to the Digital Office (Bnum), a unified portal that combines messaging, calendars, and collaborative tools. The historic URL of Mélanie2Web gives way to the Bnum portal after Cerbère authentication.
This transition occurs in ministerial waves, without a precise public timeline for the end of migration. An agent from the Ministry of Ecological Transition may already be using Bnum while a colleague from the Ministry of Agriculture remains on the old interface.
| Criterion | Mélanie2Web (historic interface) | Digital Office (Bnum) |
|---|---|---|
| Access Point | Direct URL mel.din.developpement-durable.gouv.fr | Unified portal bnum.din.gouv.fr |
| Authentication | Cerbère (password only on site) | Cerbère + 2FA mandatory outside the network |
| Integrated Tools | Messaging, calendar, address book | Messaging, calendar, collaborative tools, file sharing |
| Large File Sharing | Limited | Up to 1 GB via the integrated interface |
| Deployment | Still active for some ministries | Deployment in ministerial waves |
The comparison above shows that the available features depend on the ministry’s migration stage. Looking for a large file sharing option on the old interface while the ministry has not yet transitioned to Bnum creates unnecessary confusion.
Identifying Which Interface You Are On
The URL in the address bar remains the most reliable means. If it starts with bnum.din.gouv.fr, the agent is already using the new portal. If it points to mel.din.developpement-durable.gouv.fr, it is the historic interface that is still active.
Both interfaces share the same Cerbère credentials. Emails, contacts, and calendar events are synchronized, and the migration does not cause data loss.
Storage Quota and Attachment Restrictions on Mélanie2Web
The most common blockage is neither technical nor related to a forgotten password. A saturated mailbox simply stops receiving messages, without prior notification in most configurations.
On the historic interface, incoming and outgoing attachments are limited in size (the exact value depends on the ministry’s policy). Bnum partially relaxes this constraint with a large file sharing system that can go up to 1 GB, but this feature does not replace the management of the mailbox quota itself.
Three Reflexes to Avoid Saturation
Emptying the trash does not always free up the expected space. On Mélanie2Web, deleted items remain counted in the quota until the trash is manually emptied, and the server has recalculated the available space.
- Purge the trash and the “Sent Items” folder at least once a week, as sent attachments weigh as much as received ones.
- Archive emails older than six months locally if the email client allows it, to free up space on the server side.
- Use Bnum’s large file sharing instead of sending heavy attachments, which reduces quota consumption for both the sender and the recipient.
Security of Exchanges and Compliance on Ministerial Messaging
Mélanie2Web relies on sovereign servers hosted in France, with encrypted exchanges and traceability of connections. This architecture meets the requirements of the GDPR and the security rules specific to the administration.
No public Mélanie2Web application exists on the Play Store or the App Store. Any application claiming to offer access to Mel din from a public store is either fraudulent or unofficial. Mobile access is exclusively through the browser or through an email client configured according to the instructions of the ministerial IT service.
Attempts at phishing targeting ministerial agents have intensified in recent years. An email asking to “confirm Cerbère credentials” via an external link never comes from the administration. DIN support never asks for a password via email.
Strictness on these security points from the outset of using Mélanie2Web conditions the reliability of the entire ministerial communication chain. A compromised account does not only affect its owner; it potentially exposes the internal directory and interdepartmental exchanges.
