If only he made that much effort to get Chromium to fix the issue. The source of the problem is with a dependency of the email clients, not the email clients themselves.
He is bothering small free software projects so that those small free software projects ask Chromium to fix the issue.
The filter/search feature in Thunderbird does not appear to have a way to search for exact matches. You want exact matches. First, identify if it can do exact matches and if so, expose to the user. Else, who wants to touch that code?
He is bothering small free software projects so that those small free software projects ask Chromium to fix the issue.