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

I hate new address bk; won't let me send as before. I type in a few characters, and silly stuff gets into addr box, then mail rejected. How go bk to old way?

more options

If I type in an address list like "Amy's Relatives" I can no longer send one big e-mail to all my relatives with one click. I'll get a "no-no" remark from T'Bird saying "The recipient Amy's Relatives is not in the correct format, of Name@Domain.Com. We can't send this e-mail out." (or something like that).

This stuff didn't used to happen before late Aug 2014 or early Sep 2014.

I even had a one-person e-mail fail this morning (9/8/14) because I tried to type in a few letters, and it knew to whom to send the e-mail, but it included those few letters in the address. It made the address come out, for example, as "NJ NJABC@Yahoo.Com" when I wanted it to be just "NJABC@Yahoo.Com." This silly stuff never used to happen before.

Can we go back to a prior version of T'Bird, to stop this from happening? Or will a new version stop this -- what I consider -- huge bug?

If I type in an address list like "Amy's Relatives" I can no longer send one big e-mail to all my relatives with one click. I'll get a "no-no" remark from T'Bird saying "The recipient Amy's Relatives is not in the correct format, of Name@Domain.Com. We can't send this e-mail out." (or something like that). This stuff didn't used to happen before late Aug 2014 or early Sep 2014. I even had a one-person e-mail fail this morning (9/8/14) because I tried to type in a few letters, and it knew to whom to send the e-mail, but it included those few letters in the address. It made the address come out, for example, as "NJ NJABC@Yahoo.Com" when I wanted it to be just "NJABC@Yahoo.Com." This silly stuff never used to happen before. Can we go back to a prior version of T'Bird, to stop this from happening? Or will a new version stop this -- what I consider -- huge bug?

Chosen solution

This has been reported as Bug #1060901. It's fixed in an upcoming version of Thunderbird which is not available yet. Please read further for several options to get back a working configuration.

Several other people have sent in the same support request as you, noting this happened after they upgraded to version 31.1.

The exact error message is: XXXX is not a valid e-mail address because it is not of the form user@host. You must correct it before sending the e-mail.

This happens in Thunderbird 31.1.0 when your mailing list description includes several words separated by spaces.

Although not ideal, these workarounds should let you use your mailing lists until a proper fix is implemented:

  • While composing an email open the address book and select the list you are trying to send to, highlight all the names in the list and drag them to the To: box. This uses your existing data without modifying it.
  • Replacing the blanks " " between the words in such lists' descriptions with an underscore "_". This requires modifying your mailing list(s) description(s).
  • Downgrade to a previous version and disable automatic updates (Windows)

Going back to a previous Thunderbird release and avoiding automatic upgrades

In Windows Thunderbird updates are automatic by default. To avoid similar situations in the future, you could change that and decide to have a more conservative approach to upgrades.

Before trying anything, make a backup of your current Thunderbird profile.

You can uninstall the current Thunderbird version via Control Panel > Programs and Features and reinstall a previous version, download it from here:

Click on the type for your OS. eg: If using Windows select 'win32' then select the language eg: en-GB = English british then download the .exe file

You can customize automatic updates behavior, however, it's under Tools > Options > Advanced > Update.

My suggestion would be to set it to Check for updates, but let me choose whether to install them., specially if you depend on email for critical / important business or personal matters.

Read this answer in context 👍 1

All Replies (1)

more options

Chosen Solution

This has been reported as Bug #1060901. It's fixed in an upcoming version of Thunderbird which is not available yet. Please read further for several options to get back a working configuration.

Several other people have sent in the same support request as you, noting this happened after they upgraded to version 31.1.

The exact error message is: XXXX is not a valid e-mail address because it is not of the form user@host. You must correct it before sending the e-mail.

This happens in Thunderbird 31.1.0 when your mailing list description includes several words separated by spaces.

Although not ideal, these workarounds should let you use your mailing lists until a proper fix is implemented:

  • While composing an email open the address book and select the list you are trying to send to, highlight all the names in the list and drag them to the To: box. This uses your existing data without modifying it.
  • Replacing the blanks " " between the words in such lists' descriptions with an underscore "_". This requires modifying your mailing list(s) description(s).
  • Downgrade to a previous version and disable automatic updates (Windows)

Going back to a previous Thunderbird release and avoiding automatic upgrades

In Windows Thunderbird updates are automatic by default. To avoid similar situations in the future, you could change that and decide to have a more conservative approach to upgrades.

Before trying anything, make a backup of your current Thunderbird profile.

You can uninstall the current Thunderbird version via Control Panel > Programs and Features and reinstall a previous version, download it from here:

Click on the type for your OS. eg: If using Windows select 'win32' then select the language eg: en-GB = English british then download the .exe file

You can customize automatic updates behavior, however, it's under Tools > Options > Advanced > Update.

My suggestion would be to set it to Check for updates, but let me choose whether to install them., specially if you depend on email for critical / important business or personal matters.

Modified by Fabián Rodríguez