Learn how to forward mail on Thunderbird.
you’ve got the option to also choose to edit the message before forwarding it.
Open Mozilla Thunderbird and go to the Inbox.

snag the message you want to forward.
Double-pick the email if you want to bring up the message in a new window.
Select theForwardbutton (located in the upper-right corner of the message window).

A new Forward Message window opens.
Alternatively, selectMessage>Forwardfrom the menu, or use theCtrl+Lkeyboard shortcut (Command+Lon a Mac orAlt+Lfor Unix).
In theTofield, enter the email address or addresses to which you want to forward the message.

Trim to the body of the message if desired.
For example, to remove unnecessary email addresses or delete irrelevant content.
Add a personal message at the beginning of the message body, if desired.

SelectSendto forward the message to your recipients.
Select theThunderbird menu(located in the upper-right corner of the Mail window).
SelectOptions(located near the middle of the menu that appears).

In theOptionsmenu, select theOptionsicon to open theOptionswindow.
In the left pane of theOptionswindow, select theCompositiontab.
Select theForward Messagesdrop-down arrow.

ChooseInlineto forward messages in the body of the email window.
SelectAs Attachmentto forward all messages as attachments to emails.
Select theAdd extension to file namecheck box to send forwards as attachments.

Doing so allows your recipients to view the file throw in more efficiently.