You can email me at firstname.lastname@example.org. If you’d like something a little more secure, there are a few options:
For simple, anonymous tips, you can set up a disposable email address here, though the email address may expire before I’m able to respond.
You can always send me physical letters, files, what have you, using the U.S. Postal Service. This will often be more secure than digital methods (assuming you don’t include any identifying details). Send me stuff here:
Slate, 8th Floor
15 MetroTech Center
New York, NY 10003