Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

Avatar for Username

Mozilla サポートの検索

サポート詐欺に注意してください。 私たちはあなたに通話やショートメッセージの送信、個人情報の共有を求めることはありません。疑わしい行為を見つけたら「迷惑行為を報告」からご報告ください。

詳しく学ぶ

このスレッドはアーカイブに保管されました。 必要であれば新たに質問してください。

BT Internet SMTP refuses to work with Thunderbird

  • 3 件の返信
  • 2 人がこの問題に困っています
  • 361 回表示
  • 最後の返信者: david
  • 解決済み

Mark
Mark

I'm trying to help someone migrate to Thunderbird.

They have a BT Internet email account.

After entering the settings, incoming mail works successfully, but outgoing mail fails every time with an error.

The error is

Login to server mail.btinternet.com with username xxx@btinternet.com failed. Followed by

Sending of the message failed. Unable to authenticate to Outgoing server (SMTP) mail.btinternet.com. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'.

BT says the settings are:

Outgoing Mail Server: mail.btinternet.com Port: 465 (this may not be automatically populated on selecting SSL, so you'll need to check) SSL Encryption: Enabled (but not STARTTLS) ** I have used the SSL/TLS setting Authentication: PLAIN ** I have selected normal password Username: your email address including the @btinternet or @btopenworld.com part Password: your btinternet or btopenworld password

Have I missed something obvious? It's driving me NUTS!

I'm trying to help someone migrate to Thunderbird. They have a BT Internet email account. After entering the settings, incoming mail works successfully, but outgoing mail fails every time with an error. The error is Login to server mail.btinternet.com with username xxx@btinternet.com failed. Followed by Sending of the message failed. Unable to authenticate to Outgoing server (SMTP) mail.btinternet.com. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'. BT says the settings are: Outgoing Mail Server: '''mail.btinternet.com''' Port: '''465''' (this may not be automatically populated on selecting SSL, so you'll need to check) SSL Encryption: Enabled (but not STARTTLS) '''** I have used the SSL/TLS setting''' Authentication: PLAIN ** I have selected '''normal password''' Username: your email address including the @btinternet or @btopenworld.com part Password: your btinternet or btopenworld password Have I missed something obvious? It's driving me NUTS!

選ばれた解決策

FINALLY found the problem! Turns out every time I tried to copy and paste the password it added an extra space character at the end. As there is no "show password" option it wasn't easy to spot. However, as the correct password was already entered and working for IMAP, and I used the TB setup wizard I don't understand why it didn't use the correct password it already had, or why that failed in the first place!

Thanks for your help David!

この回答をすべて読む 👍 0

すべての返信 (3)

david
david
  • Top 10 Contributor

Have you tried 587 and starttls? or 587 and ssl/tls?

Mark
Mark 質問者

選ばれた解決策

FINALLY found the problem! Turns out every time I tried to copy and paste the password it added an extra space character at the end. As there is no "show password" option it wasn't easy to spot. However, as the correct password was already entered and working for IMAP, and I used the TB setup wizard I don't understand why it didn't use the correct password it already had, or why that failed in the first place!

Thanks for your help David!

david
david
  • Top 10 Contributor

I'm glad all worked out.