From the bug report , which also has a screen shot mock up "This would make it easier to identify the folders of diffrent mail accounts. This would also make sense for the top account nodes."
@volkersaggau it would be helpful for you to clarify the actions you expect, step by step.FWIW there are some well known signature addons https://addons.thunderbird.net/EN-US/thunderbird/search/?q=signature+&appver=&platform=
@jeffrollason it is unlikely that https://addons.thunderbird.net/en-US/thunderbird/addon/removedupes/ will be built into Thunderbird soon. But the add-on is still going strong and has had several updates. If you are still getting multiple messages,...
Thank you for this idea.There are not currently plans to add spam processing to the mobile application. But I see there are several standalone apps, some of which run on phone, for example SpamDrain, Cleanfox / Clean Email, MailWasher, Inbox Zapper,...