It looks like your Inbox is acting like a Drafts folder. See if you can fix it with FolderFlags:

https://support.mozilla.org/en-US/questions/1460237

sfhowes,

I tried your suggestion and received a msg that folderflags extension IS NOT compatible with my version of TB - 128.3.3esr (64-bit).

My other TB extensions are compactheaders and importexporttools NG

Mike A.

For TB 128, install FolderFlags 1.7.0:

https://addons.thunderbird.net/en-us/thunderbird/addon/folderflags/versions/

https://support.mozilla.org/en-US/kb/installing-addon-thunderbird

sfhowes,

I wound up taking a different path to solve this. 1) I did a complete back up of the messages in the inbox by copying them to another drive. 2) 'rolled back' the entire drive to an older version [about 3 weeks] (I use clonezilla for system back up). 3) Began to methodically selecting and copying select messages to the inbox using exportimport toolsNG.

So far I have not experienced the "draft" problem anymore.

Not to be critical, I don't see how your suggested extension could help.

Mike A.