IMAP settings · btinternet.com · btopenworld.com · talk21.com
BT Mail IMAP settings
BT serves its mail from a single host for both directions: mail.btinternet.com, port 993 for receiving and 465 for sending. Older BT addresses — btopenworld.com, talk21.com — were never moved anywhere else and connect exactly the same way.
IMAP connection
- Server
- mail.btinternet.com
- Port
- 993
- Encryption
- SSL/TLS
- Username
- full address
- Password
- the mailbox password
Sending, SMTP
- Server
- mail.btinternet.com
- Port
- 465
- Encryption
- SSL/TLS
Checked against the service's own autoconfiguration file on 2026-09-15 — the same source Thunderbird reads when it fills the settings in for you. Source: autoconfig.thunderbird.net
What breaks here.
- There is no separate imap. or smtp. host. Both directions go to mail.btinternet.com; the port is what differs.
- btopenworld.com and talk21.com addresses use the same settings as btinternet.com.
- The username is the full address, not the BT ID you sign in to the website with.
- A BT mailbox is tied to the broadband account. When the line is cancelled the mailbox goes with it unless you have moved the mail first.
Questions
The short answers
What is the incoming server for BT?
mail.btinternet.com on port 993 with SSL/TLS, using your full email address as the username.
Do I need an app password?
No. BT accepts the mailbox password over IMAP.
And for sending?
The same host, mail.btinternet.com, on port 465 with SSL/TLS and authentication enabled.
I am switching broadband provider — will I lose the mail?
The address can stop working once the line closes, so copy the mailbox to another provider before that happens. The transfer keeps folders, flags and dates.
Find out how big your mailbox is. It costs nothing.
Connect two servers, look at the size and decide. Or take the client and keep everything on your side.
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