[ktpsns]

That's why most folks I know either write a short latex file (and append pdf+tex) or write pseudo code or full latex code because... The recipient understands latex.

But honestly, this is way more portable then mathjax or MathML or whatever. Consider using a latex enabled chat when it really differs.

[svat]

Yes, those were two other options I considered. Ultimately both require higher effort from the reader (view the PDF, or mentally parse LaTeX syntax or have something special installed that does so), neither of which is conducive to quick skimming etc. Just optimizing for reader convenience. :-)