I now assume you didn’t write the email by yourself. It will be harder than ever to earn the courtesy of a reply from your recipient. The longer your email, the more surface area it exposes to a human brain’s bot detection. Therefore, what you write in your first email is critically important.
If you are writing to a human, write like one.
Cold emails written by bots quote generic lines from your webpage. They lean on HTML with heavy pill badges. They also force connections between their pitch and your own pages. They are not generic emails, but a failed attempt at personalisation.
Long emails are a waste of time. For the writer as well as for the reader. The goal is to communicate your idea with as few words as possible. Two-paragraph emails are ideal. Keep both paragraphs under three sentences. In the first paragraph, talk about what interests your recipient. In the second, what you want to share or discuss with them.
The most sinister act is to spam them. It’s the speediest way to lose trust. The other drawback is that your emails will become harder to get through. If you’re unintentionally doing it, just pause and ask yourself. If you received this email with your busy schedule, would it add value? Information overload is a reality. Being concise and valuable is the most helpful thing you can do.
Does that mean long emails are completely useless? Yes. I do read long emails sometimes, but most of them now seem to be written by bots. If you think you can trick people, you’re wrong. Spotting slop is not rocket science and humans are inherently good at finding patterns. These patterns are easy to detect. If you didn’t write the email yourself, you didn’t make it detection-proof either. The sooner you realise this charade isn’t worth playing, the better writer you’ll become by doing the work yourself.
I understand that when a security researcher needs to disclose a vulnerability, it has to go through a private channel like email and must contain all the details to reproduce the flaw. In this case, email is the usual format, but any private channel could have done this communication. But I wouldn’t call it the canonical way to use email. It’s just the format everyone happened to settle on, because security flaws are older than the internet, so email took precedence.
All communication around email has gone through quite a few phases. One thing that sticks as wisdom: writing less is more.