Sent and Deleted may not come into existence until you need them. Have you sent or deleted a message yet?

Maybe you can't see the folders.

First of all, I recommend you set up the regular menus, and the toolbars.

http://chrisramsden.vfast.co.uk/13_Menus_in_Thunderbird.html

Then check View|Layout|Folder Pane is selected

Then check View|Folders|All is selected too.

If by "groups" you mean a Mailing List, you just enter the List's name in place of an email address. (I don't think there is any easy way to import Groups from other email programs.)

Here are some words from my website about using the address book in Thunderbird:

There are several ways to use Thunderbird's Address Book.

Open the Address Book, select an address book, select a Contact (or several Contacts) and click the "Write" button (in the Address Book). This will create a new message, with the selected Contacts added to the To: address boxes. This approach has two major disadvantages; it can only be used to start a new message (it's of no use when replying or forwarding) and all the addressees are placed in the To: box, which is undesirable, unless you know for sure that all of these addressees have consented to their addresses being shared amongst them. This is fine between colleagues in the workplace, but unacceptable with friends' private email addresses.

If you select a Mailing List and click on "Write", then again a new message will be created, this time with the Mailing List's constituent Contacts all filled into the new message's To: boxes. This might be useful if you wanted to omit a Contact from a group mailing.

As mentioned above, there is an autofill system. Another way to use your Address Book is to start a new message (it could also be a reply or forward). If you don't want to send using To:, click on To: and alternative sending modes – Cc:, Bcc: etc, will appear. Select one, then just start typing a name or address into the address box. Suggestions that match what you've typed will appear. Move to the correct address and click it or press return, the address will be filled in and the cursor will advance to the next line. Even though there are, typically, only four address lines on show, Thunderbird will keep adding new lines and offer a scroll bar to allow them to be seen. You can grab and drag the top edge of the message text pane down to make more room for the display of addresses.

If you prefer a visual prompt, then when composing a message, use the F9 key, or via the compose window's menu:

View|Contacts Sidebar

and a sidepane will show you a compact view of one of your address books. You can now select Contacts, and use the Add to... buttons at the bottom, or drag-and-drop Contacts into an address box, or right-click and select an option from the context menu.

Mailing Lists will appear intermingled with your discrete Contacts, and can in principle be used in place of a Contact to stand for all the member Contacts stored in the Mailing List. The sending mode will be applied to each of the member Contacts within a Mailing List, so if you send to a List using Bcc:, it will act as if each of the Contacts named in the list was individually addressed using Bcc:.

BTW there has been a mailing lists bug reported as Bug #1060901. If you have an account on Bugzilla, please consider voting for that issue.

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)

Thank you for your support but we are unable to get a SENT box up. We have all the other tools in the list for emails but no SENT box. Yes, we are constantly sending and deleting emails. Help?