Have you tried long-pressing the text? You should get a pop-up with various choices, including Forward. Tap Forward, then enter the e-mail address that you want to forward the text to in the To line and press Send.
I don't see anything but a trash can at bottom. Forward doesn't show up. I am pressing on the thread (before it's open). I tried opening thread but no options to forward entire thread.
I see my original question was not specific enough- sorry. I want to send all my threads to somewhere they can be printed out. I'm changing devices (not number) and I believe my texts will no longer be available
is that right or wrong?.
Are you using Android? If so, you might try SMS Backup & Restore - Android Apps on Google Play to back up your texts, restore them to your new device, and have an option to print them if you wish. If you aren't using Android, there might be a similar app in the respective app store.
SMS Backup and Restore backs up all of your texts. When restored to your new phone, they should be back as threads; when printed, they appear in a spreadsheet.