I prefer email over other messaging systems. Whenever my computer is on, my email client is open. I usually respond within 24 hours but sometimes it may take a day or two.
My email address is arh at gnu dot org. It’s best to encrypt your message even if your message is not important. Use my PGP key to do so. Also, you should send me your public key so I can encrypt my messages to you too.
I also post toots (like tweets) on Mastodon. My handle is @firstname.lastname@example.org.
Don’t ask me to promote your product unless it’s free software. Don’t ask me to publish your article or share your notes unless it’s for public benefit. I won’t link to your blog if you blog is commercial or promotes proprietary software.
Send your messages in plain text. Don’t send HTML messages. If you send me a link to your message, I won’t open it. Please don’t send files I haven’t asked for. I won’t open any file unless I’ve asked for it.
You don’t need to be so polite. A simple ‘hello’ is good enough but even that is not necessary.