You can send email to jdt at this domain. I also get emails through ucsc and uwaterloo (jtracey and j3tracey respectively), which you can use if it's something academically related. I have two gmail accounts, but I'm more likely to see emails to one of the above.
I have a few mastodon accounts:
A CrySP account, for anything related to my research.
An OpenStreetMap account, for things relevant to my mapping hobbies.
A general account, for everything else.
I tend to keep a pretty close eye on my GitHub account. I have accounts on other git providers and the like as well, but I don't monitor them as closely, so if you want to contact me about something on one of them, you'll likely have better luck using one of the other options listed here.