My client likes to use html symbols and emojis in their subject lines. As we all know, not every animation is treated equally in every email client.

Some email clients such as early Outlook don't display at all, others will only display in black, and some in vibrant colors.

So my goal is to compile a list of web safe sybols and emojis and include how they render in each major email client.

Does anyone have any documentation on this?