Your first email should include "Metamath" in the subject to add you to my spam filter's whitelist.
Unfortunately, MIT has its own aggressive pre-filter that sometimes blocks valid emails as spam and that I can't disable. To guarantee that I will receive your email until I add you to their whitelist, you can also contact me via =nm (which is my permanent i-name). Remember to include your email address inside the message.
When possible, I prefer plain text email (not HTML formatted).
My postal address is:
19 Locke Lane
Lexington, MA 02420-2706