Use the settings in Cedros to connect your hosted mailbox to a mail app that supports IMAP with SSL/TLS and authenticated SMTP. You will create an app password, enter incoming and outgoing settings, and check delivery in both directions.
If you use Apple Mail on Mac, Mail on iPhone or iPad, or Outlook, follow that app's guide. This article covers the general setup and includes examples for Thunderbird on a computer and the Gmail app on Android.
These instructions apply to Cedros-hosted email. If your mailbox is hosted by Google Workspace, use your app's Google account option and Google sign-in instead. See Choosing Cedros email or Google Workspace if you are unsure which applies.
Before you begin
Confirm that the mailbox is Active and works in Email → Inbox in Cedros. If you need to create an address first, follow Creating personal and shared email addresses.
Have the following ready:
- The full mailbox address, including the domain.
- The server hostname shown in Cedros for the mailbox.
- A Cedros app password for this device or connection.
- An outside email account you control for a send-and-reply test.
A receiving alias has no separate mailbox password. Use the actual mailbox address when signing in. For a shared address, confirm that you have permission to connect it and obtain a credential from the administrator if needed.
Adding a mail app does not move messages from your previous provider or switch your domain's incoming delivery. Complete Importing existing email into Cedros separately if you need old messages. This connection is for email; it does not configure Cedros calendars or contacts.
If the app offers cloud syncing or copies of mail on its own service, review that choice before continuing. Follow your organization's requirements for where work email may be stored.
Get the settings and an app password
- Open Email → Inbox → Settings in Cedros. Under Your mail → Your addresses, find the mailbox and select Connect mail app.
- Keep the Mail client settings dialog available. Copy settings copies connection details, including the hostname and ports, but does not copy a password.
- Select Open app passwords, or use App passwords… from the mailbox's actions. If you cannot issue a password, ask your administrator. They can also use Team → Mail addresses → App passwords….
- In What is this password for?, enter a recognizable label such as “Thunderbird on laptop.” Leave Expires empty unless you want this credential to stop working at a particular time.
- Select Create app password. Save the One-time app password securely, then select I’ve saved this password before closing the dialog.
The password is shown once, but it remains valid until it expires or is revoked. Use it for both incoming and outgoing mail. Your Cedros sign-in password will not work for this connection.
Create a separate app password for each independently configured device or connection. Do not use Replace all… just to add a mail app: it revokes every existing app password for the mailbox and interrupts other connections.
If the hostname is missing or the mailbox is still provisioning, ask the administrator to finish setup before connecting.
Enter the connection settings
Use the same Cedros hostname and mailbox credentials for receiving and sending:
| Setting | Value |
|---|---|
| Incoming account type | IMAP |
| Incoming and outgoing server | The hostname displayed in Cedros |
| Incoming and outgoing username | Your full mailbox address |
| Incoming and outgoing password | The Cedros app password for this connection |
| Incoming port and security | 993, SSL/TLS |
| Outgoing port and security | 587, STARTTLS |
| Outgoing authentication | Required, using the same mailbox address and app password |
For outgoing mail, Cedros also supports 465 with SSL/TLS. Choose that pairing if your app offers SSL/TLS instead of STARTTLS for SMTP. Do not pair port 587 with implicit SSL/TLS or port 465 with STARTTLS.
Enter only the hostname in a server field when the app has a separate port field. Do not add https://, a webmail path, or a guessed mail. prefix. Use hostname:port only if the app specifically requires that combined format, replacing “hostname” with the value Cedros supplies.
An authentication choice labeled Password or Normal password means the app submits the Cedros app password. It does not mean your Cedros sign-in password, and it does not turn off connection encryption. Keep SSL/TLS or STARTTLS enabled separately. Do not select OAuth2, a certificate-based login, or Secure Password Authentication (SPA) for this setup.
Choose IMAP rather than POP or Exchange. Use incoming port 993 and one of the outgoing pairings above; ports 143 and 25 are not the client connection settings for this setup.
Connect the mailbox
The labels differ by app, but the sequence is usually:
- Open the app's account settings and choose to add an existing email account. If a provider list appears, choose Other, IMAP, or the manual account option.
- Enter your display name, full Cedros mailbox address, and the app password. The display name is what recipients see beside your address; it is not the login username.
- If automatic setup fails or finds another provider's servers, open manual or advanced settings. Select IMAP and enter Cedros's incoming hostname, full username, app password, port 993, and SSL/TLS.
- Configure SMTP separately with the outgoing settings above. Enable authentication or a setting such as Require sign-in. Fill the username and password even if the app labels them optional.
- Make sure this mailbox uses the outgoing server you just configured. When several accounts exist, a default server from another mailbox can cause sending failures or the wrong sender.
- Run the app's connection check, save the account, and allow its folders and messages to load. Correct errors before continuing to the delivery test.
An app that accepts only a Google, Microsoft, or Exchange sign-in cannot use these manual Cedros settings through that account option. Look for a supported IMAP option or ask your administrator which app to use.
If the app reports an insecure connection, an unknown certificate, or a hostname mismatch, keep encryption enabled and have the error resolved. Do not choose an unencrypted connection or accept an unexpected certificate to finish setup.
Examples in common mail apps
Thunderbird on a computer
Start from Thunderbird's menu: New Account → Existing Email. Some versions also offer Account Settings → Account Actions → Add Mail Account. Enter your name, Cedros mailbox address, and app password, then continue.
Choose Manual Configuration to check the incoming IMAP and outgoing SMTP details against the table above. Select Normal password where offered, enter the full address for both usernames, and use Re-test before finishing.
If the incoming account works but sending does not, open Account Settings → Outgoing Server (SMTP). Check the Cedros entry and confirm that the mailbox uses it. Keep the username specific to that mailbox, even if another account uses the same hostname.
Mozilla's account setup guide and manual configuration guide explain these controls. Use Cedros's settings, not server examples for another provider.
Gmail app on Android
In the Gmail app, tap your profile picture, then Add another account → Other. Enter the full Cedros mailbox address and choose Personal (IMAP). Supply the Cedros app password and use the incoming settings above. Complete the outgoing server screen with the same full address and app password, authentication enabled, and the correct SMTP port/security pairing.
Use Google's Android account setup guide if the entry point differs on your device. Adding a Cedros mailbox this way lets the Gmail app display it; you are not connecting the mailbox through Cedros's Google Workspace integration. If a security warning appears, correct the connection rather than selecting None for security.
Test delivery and check stored folders
- From an outside account you control, send a new message with a distinctive subject to the Cedros mailbox.
- Confirm it appears in Email → Inbox in Cedros and in the correct inbox in your mail app. Refresh the app and allow the initial synchronization to finish.
- Reply from the app, checking that From is the Cedros mailbox address. Confirm the reply arrives at the outside account with the expected sender.
- Reply once more from the outside account and verify its arrival in the app. Test a small attachment if you use attachments regularly.
- Check Sent and any folders you rely on in both the app and Cedros. Save a harmless draft and check whether it is available in Cedros if you need drafts across devices.
A successful connection check or a message in Sent does not prove delivery to the outside recipient. If sending also fails inside Cedros, review Setting up outgoing email delivery with your administrator.
IMAP synchronizes server mail between connected apps. Deleting or moving messages can change what you see elsewhere; a local downloaded copy is not a separate backup. Folders stored only on the device are not automatically uploaded to Cedros. Mozilla's IMAP synchronization guide explains server and local storage.
For Thunderbird, Copies & Folders controls where sent messages and drafts are saved. Select folders belonging to the Cedros account if you want those copies available through Cedros and other devices. See Mozilla's account configuration options.
Fix common problems
The password is rejected. Check the full mailbox address and app password in both server sections. Remove copied spaces and confirm that the credential belongs to this mailbox. Replace an expired or revoked password. A successful browser sign-in to Cedros does not test the separate app password.
Receiving works, but sending fails. Check SMTP authentication, its username/password, the selected outgoing server, and the port/security pairing. Use the mailbox address as From rather than assuming an alias is authorized to send. If the message remains in Outbox, correct the connection and retry before judging delivery. Follow Why can I receive email but not send it? if the problem remains.
The server cannot be reached or its certificate is rejected. Compare the hostname exactly with Cedros's displayed value and check internet access. If the failure happens only on one network, tell the administrator. Keep encryption and certificate checks enabled.
Messages appear in Cedros but not in the app. Check the selected account, folder, filters, sync schedule, and folder subscriptions. Some apps download only a limited date range or need folders selected for offline use. If messages are absent from Cedros too, review mailbox status and missing incoming email. If only older messages are missing from the app, open one in Cedros and check for an encrypted cold-storage notice. Follow Read or restore a cold-stored message if you need a local copy in the app.
A folder or old message is missing everywhere in Cedros. Check whether it still exists at the previous provider or only in a local archive. Adding an account does not import that history. Keep the old copy until the separate import is complete and checked.
The setup controls are unavailable. Ask the Cedros administrator for an app password or your device administrator about restrictions on adding accounts. Do not remove workplace management controls to complete setup.
Avoid removing and re-adding the account as the first troubleshooting step. Confirm that important mail is available in Cedros or safely saved elsewhere, and preserve local-only drafts, archives, and unsent messages.
For help, provide the app name and version, operating system, mailbox address, displayed hostname, exact error, and whether sending, receiving, or both fail. Keep passwords and private message contents out of the report. See Getting help and reporting a problem.
Replace a password or disconnect an app
For step-by-step credential changes, follow Creating, replacing, and revoking email app passwords.
For routine replacement, create and securely save a new app password, update the app's incoming and outgoing credentials, and repeat the delivery test. Revoke the old credential when the new connection works.
If a device is lost or a connection should stop accessing mail, use Revoke for its labeled app password in Cedros. Revocation stops that credential from authenticating; it does not erase messages already downloaded or copied to another service.
Removing the account from the mail app is a separate action and does not close the Cedros mailbox. Read the app's removal prompt and save any device-only data first. Use Replace all… only when you intend to revoke every existing app password for the mailbox.