The IMAP protocol allows for the synchronization of an email inbox across multiple devices without deleting messages from the remote server. For staff at the Académie de Nantes, this means accessing professional emails from a smartphone while still retaining access via the usual webmail. The configuration relies on two distinct blocks of settings: an incoming server (IMAP) for receiving and an outgoing server (SMTP) for sending.
Académie de Nantes or Nantes Université: two mail systems, two servers
A common confusion is to use the settings from Nantes Université to configure a national education account. The two entities use separate email infrastructures. A teacher or administrative staff member associated with the Académie de Nantes must use the academic servers, not those of the university.
Before adjusting the phone settings, it is useful to first connect to the academic webmail from a browser. If the connection fails at this stage, the issue lies with the password or the account itself, not the mobile client. This preliminary check avoids searching for a configuration error where there is none. The IMAP settings for webmail ac Nantes rely on servers specific to the academy, distinct from any other Nantes institution.
IMAP server and SMTP server of the Académie de Nantes: the values to enter
The IMAP protocol only handles receiving. The SMTP protocol only handles sending. Configuring one without the other gives the impression that the account is functioning, until one attempts to reply to a message.
Receiving (IMAP)
- Incoming server: imap.ac-nantes.fr
- Port: 993
- Security type: SSL/TLS
Sending (SMTP)
- Outgoing server: smtp.ac-nantes.fr
- Port: 465
- Security type: STARTTLS (on some Android clients) or SSL/TLS depending on the application used
The username corresponds to the academic identifier, usually in the form firstname.lastname (without the domain @ac-nantes.fr in most clients). The password is that of the webmail account.
IMAP configuration on Android: steps and bottlenecks
On Android, the email application varies by manufacturer. Samsung, Xiaomi, and Google each offer their own mail client. The procedure remains similar in broad strokes.
Open the default mail application, then choose “Add an account”. Select “Other” or “IMAP” (not Exchange, not POP3). Enter the full address ([email protected]), the password, then the incoming and outgoing servers described above.
The most common bottleneck on Android concerns security certificate errors. Some third-party clients (like FairEmail or K-9 Mail) display a warning when the certificate from the academic server does not exactly match the expected name. Accepting the certificate manually resolves the issue in most cases, but one must first verify that the entered server name is correct.
Another frequent pitfall: the “security type” field of the SMTP server. Depending on the application, the options presented are STARTTLS or SSL/TLS. If sending fails with one, test the other before changing anything else.
IMAP configuration on iPhone: specifics of the native Mail client
On iPhone, the Mail application integrated into iOS manages configuration in a more structured way. Go to Settings, then Mail, then Accounts, then Add Account. Choose “Other”, then “Add Mail Account”.
iOS successively asks for the name displayed in sent messages, the full email address, the password, and then a free description of the account. The next screen displays two tabs: IMAP and POP. Select IMAP.
Then enter the incoming and outgoing servers with the same values as on Android. iOS automatically detects the port and encryption in most cases, which simplifies the process compared to Android. If automatic detection fails, manually force port 993 for IMAP and 465 for SMTP.
A peculiarity of iOS: the Mail application may display “Cannot verify the identity of the server” during the first connection. Pressing “Continue” allows you to finalize the configuration. This message appears when the certificate from the academic server is not included in Apple’s default trust list.
Testing the end-to-end configuration
Receiving a message does not prove that the account is fully functional. Sending and receiving must be tested separately. Send a message from the phone to a personal address, then reply from that personal address to the academic account.
If receiving works but sending does not, the issue lies with the SMTP server: wrong port, wrong security type, or incorrectly entered identifier in the outgoing section. If sending works but not receiving, check the IMAP server and port 993.
IMAP synchronization may take a few minutes before displaying all folders. Subfolders created in the webmail sometimes appear with a slight delay on the mobile client, without indicating a malfunction.
The IMAP protocol keeps messages on the academic server. Deleting an email from the phone also deletes it from the webmail, and vice versa. This bidirectional synchronization is precisely what distinguishes IMAP from POP3, where downloaded messages are removed from the server.
