Not a dominant email client, but it is what I use myself. Just leaving a few notes here for now.
This gist shows the Thunderbird div class.
<div class="moz-cite-prefix">On 2/19/2020 3:53 PM, John Smith wrote:<br>/div>
<blockquote type="cite" cite="mid:345egdf_sdfsEbyVitCvsgsdvdkht6HHg@mail.gmail.com">
-- original message here --
</blockquote>
Not a dominant email client, but it is what I use myself. Just leaving a few notes here for now.
This gist shows the Thunderbird div class.
https://gist.github.com/b-alidra/73a5080c2f90243a9d2e9f7ad370df53