If company can't be bothered to learn how to send email properly, their email will just go to trash, thank you. :) Things like: - sending empty plaintext part

If company can't be bothered to learn how to send email properly, their email will just go to trash, thank you. :) Things like: - sending empty plaintext part or differnt content in plaintext part and html parts within multipart/alternative subparts (https://www.freesoft.org/CIE/RFC/1521/18.htm https://www.freesoft.org/CIE/RFC/1521/18.htm) - pretty much only some automated/marketing email is guilty of this. normal senders always get it right - sending 5 line uncopiable tracking link in plain text (links should be shorter than 80 chars, to not annoy anyone trying to copy paste them) - sending broken html just because it maybe renders some insane table layout in outlook 97 from 50 years ago more "nicely"