When 'plain text' is selected in preferences, the following is included in the email:
<span lang="en" dir="ltr">Wikimedia Foundation, 149 New Montgomery St., 3rd Fl., San Francisco, CA 94105 (USA).</span>
The change was this recent commit:
https://gerrit.wikimedia.org/r/#/c/90934/2/wmf-config/InitialiseSettings.php,unified
Version: unspecified
Severity: normal
The WMF core features team tracks this bug on Mingle card https://mingle.corp.wikimedia.org/projects/flow/cards/391, but people from the community are welcome to contribute here and in Gerrit.
It's not only when plain text is selected. The multi type message with HTML also has a text version that displays the HTML as plain text.
It can be resolved in a simplistic way by changing the value to "Wikimedia Foundation, 149 New Montgomery St., 3rd Fl., San Francisco, CA 94105, USA". Without any punctuation in the beginning and the end, there won't be any RTL issues.
If there is a way to have different values for text emails and for HTML emails, then the text email should have this simple text without punctuation in the end and the HTML should have the proper HTML tags.
Another possibility is to add the LRM character (U+200E) in the end.
Change 96392 had a related patch set uploaded by Bsitu:
Remove html tag from echo email footer address