This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

multiple o boxes

  • 1 reply
  • 1 has this problem
  • 1 view
  • Last reply by Stans

more options

When I enter an email address in the to box another to box automatically appears. I have just installed thunderbird on a new windows 10 computer and this does not happen in the new installation and I cannot find a setting which enables it.

When I enter an email address in the to box another to box automatically appears. I have just installed thunderbird on a new windows 10 computer and this does not happen in the new installation and I cannot find a setting which enables it.

All Replies (1)

more options

Chosen Solution