Regarding the overriding of a message's design with the theme-based reset: Are bulk precedence messages excluded? As they are more likely to be "designed" (and spam-laden mails using CSS obfuscation are effectively filtered already by Gmail, and thus shouldn't be a primary concern), I would humbly suggest excluding bulk or transactional precedence (changing styles of an invoice could complicate a vendor's life when the "reset" version doesn't look like a standard invoice, for example) emails from this trickery.<p>Are emails with certain CSS or markup designed for accessibility excluded? If I carefully selected a high contrast design, with heavy stroke-weight fonts because my recipient is vision impaired, or I included specific ARIA landmark roles or other markup, and that markup's semantics are changed when the presentation is changed ... Is Gmelius going to blindly overrule these considered choices?<p>Can a user choose to exclude senders from having their styles overridden, or themselves change the overriding style sheet? Maybe their contacts list senders don't get overruled?<p>It's bad enough that ISPs inject themselves into web sites, please don't believe that you are harmlessly changing things for the better. Unless you've got serious design and accessibility knowledge that will ensure emails' design intent or accessibility for disabled users aren't affected, it seems like a needlessly complex and burdensome thing to manage.<p>Of course, maybe your target audience doesn't care, or knows that accessibility is affected and proceeds anyway. I certainly don't assign malicious intent to the extension, either way. I think it's a nice collection of user styles/user scripts, and if I wasn't already using a different client, I'd at least experiment with your additions (after turning off that vexatious CSS reset, ugh, that kind of thing really bothers me).<p>TL;DR: Well done. Please consider using bulk/transactional precedence (used by most legitimate commercial senders) and/or user overrides via whitelist or de-facto lists like contacts to exclude emails from having their styles overruled.