Or run this command to automatically download my GPG key and add it to your keyring:
curl -L https://lukesmith.xyz/lukegpg.gpg | gpg --import
I will eventually see emails so that is the most persistent way to contact me (I don't have caller ID).
As for people I only know on the internet, I get many, many emails a day, even when I am inactive on YouTube. I can't respond to all or most of them. If you want me to respond to yours, here's a guide. These aren't rigid rules, but they're generalizations that have arisen as I've begun to get so much mail.
I highly appreciate long fan mail, and I will read it happily, but don't necessarily expect a personalized response. Don't get deterred if I don't return an email; it still means a lot to me.
Put yourself in my shoes, I don't necessarily know where you are, and I do get a lot of mail like that, so the most honest thing I can usually do is respond to people's excitement with a tepid-sounding "Hey thanks!" just because I don't really know you! Emails like these are still meaningful to me and if you have some thanks to say to me, please do and it does affect my work positively and often I get important insights in to what people benefit from too.
Unless you really understand me and my channel, specifically the kind of software I use and recommend, don't even bother contacting me to shill your product. I get a lot of requests for me to review software for Windows or software that is proprietary or absolutely contrary to my preferences. If you actually understand what's going on on my channel and want to send me a product to review, you should first prove to me that you are who you say you are in your email. I'm not going to expose the location of the cabin to some random person LARPing. Please provide your GPG key and encrypt using mine. If you don't know what that means, you probably shouldn't even bother trying to sell me something.
Occasionally my humble domain will be marked by some email services as spam. Check your spam messages or whitelist my domain to ensure you see my response.
I don't think happens anymore since I integrated OpenDKIM into my email system, but I'll say it just in case.