I have a client who has been using HTML signatures for their email for a while, but at first the changes were infrequent, so I made do with editing the HTML files by hand. After a while the changes started to happen more frequently, so I set up a database for the users and used PHPAddEdit to power the form for entering the data into it. Datatables was used to list the users in the database and I have also added links for viewing, deleting and editing the data. The changes then seemed to get even more frequent, so I had to add a download link, so that the HTML could also be downloaded and put into the file share, that the Thunderbird users are getting their signatures from. The HTML has been inserted into the PHP code in a way that makes it easy to change.