The easiest way is by email. I shan't make the email address clickable on this page, or spam harvesters will find it, and I'll be even more flooded with spam. But here's something that only humans can figure out (so far): you can email me at dennislist at fastmail dot fm, replacing at and dot with the usual symbols.
Also, if you have never emailed me before, please don't include any attachments - the spam filter will delete them, because most attachments from strangers are viruses. If you need to send an attachment, just ask beforehand.
By mail: to reach me the old fashioned way, my address is 1 East Tce, Nailsworth, Adelaide, SA 5083, Australia