Knowledge base
Thunderbird
Add an address to Thunderbird on Windows, macOS or Linux, field by field, and set its folders to work the way OpenEmail does.
Before you start
- You need an app password for the address, made in the Passwords view of its Mail apps tab under Settings → Addresses, or a setup link someone emailed you.
- These steps follow Thunderbird 115 and later, which look the same on Windows, macOS and Linux.
Add the account
- Open the menu, then Account Settings, then Account Actions, and choose Add Mail Account.
- Enter Your full name, the whole address as Email address and the app password as Password. Keep Remember password ticked.
- Choose Configure manually. Thunderbird looks for servers on the address’s own domain and finds none, so it needs them by hand.
- Fill in Incoming Server and Outgoing Server exactly as in the tables below.
- Choose Re-test. Thunderbird connects to both servers and confirms the settings.
- Choose Done. If Thunderbird asks for the password, enter the app password.
| Incoming Server | Value |
|---|---|
| Protocol | IMAP |
| Hostname | imap.openemail.uk |
| Port | 993 |
| Connection security | SSL/TLS |
| Authentication method | Normal password |
| Username | The whole address |
| Outgoing Server | Value |
|---|---|
| Hostname | smtp.openemail.uk |
| Port | 465 |
| Connection security | SSL/TLS |
| Authentication method | Normal password |
| Username | The whole address |
To use POP3 instead, set Protocol to POP3, Hostname to pop.openemail.uk and Port to 995. POP3 downloads only the inbox, so use it only when IMAP is not an option.
Set the folders
Thunderbird recognises Sent, Drafts, Archive, Junk and Trash by itself. Three settings are worth checking in Account Settings for the account:
- Copies & Folders, Archive options: choose A single folder. Otherwise Thunderbird files archived mail into a folder per year, such as Archive/2026, and each of those becomes a label for the whole workspace. With a single folder, archiving lands in Archive, as it does in OpenEmail.
- Copies & Folders, Place a copy in: leave it on Sent. OpenEmail files its own copy of what you send and recognises the one Thunderbird saves, so Sent keeps one.
- Server Settings, When I delete a message: keep Move it to this folder, set to Trash, so deleting moves the conversation to Trash, which is Bin in OpenEmail. With the other two choices, deleting from Inbox archives the conversation instead.
Every label of the workspace shows as a folder, and a folder made in Thunderbird becomes a label for everyone. Every folder starts out subscribed, so new labels appear without a visit to Subscribe.
How new mail arrives
- With Allow immediate server notifications when new messages arrive on, under Server Settings, Thunderbird keeps a connection open and new mail shows within about 20 seconds.
- Check for new messages every, in the same place, sets how often Thunderbird looks at the other folders.
Add the calendar
The calendar in Thunderbird connects over CalDAV with the same address and app password.
If it does not work
- Re-test fails on the incoming server: check that Connection security is SSL/TLS, not STARTTLS, and that the port is 993.
- Re-test fails on the outgoing server: check that the port is 465 with SSL/TLS. Thunderbird often suggests 587 with STARTTLS, which OpenEmail does not offer.
- Login to server failed: the username must be the whole address and the password an app password that has not been revoked. To clear a saved password, open Settings, Privacy & Security, Saved Passwords, and remove the old one.
- The app asks for the password again and again: the password was revoked, or sign-ins paused for up to 15 minutes after too many wrong passwords. Correct the password in the app, then wait before trying again.