I'm going to add a 3rd opinion here :)
1) Short and sweet (keep it to 3-4 sentences)
2) Start by briefly summarizing who you are and flagging your interest in the company
3) Add a unique spin (something particular about the company that interests you, some way you're connected to the company, etc. etc.)
4) Leverage #3 to ask if there's anyone who they can put you in touch with to better understand that side of the company
For #3, this could be anything geography-based, diversity-based, function-based, initiative-based (like social impact programs, etc.), etc. etc. Find something unique that shows you did your research and gives you an "excuse" to talk to someone!