TL;DR: sign up for Fastmail (referral link), and then follow these instructions and everything will be dandy.
I’ve used various methods over the years to be able to receive emails from addresses at custom domain names (such as boss@treylabs.com). I don’t want to tie all my emails to a particular, custom address—I just want the addresses to be forwarded to my actual email hosting. For many years, that was Gmail. Now, it’s Fastmail.
For the past few years, I had been using Hover’s $5/address/year email forwarding service because it was the most obvious solution that I knew of at the time. This worked just fine until it didn’t. On a couple of occasions (that I know of), some emails that I expected would never appear. After lengthy chats with Hover’s technical support, they determined things were marked as spam and filtered out before they were forwarded. Marking things as spam is fine and good, but not without a way of getting at the falsely flagged items.
Once I was given access to see the flagged messages, almost none of them were actually spam. Hover’s proposed solution to this problem was for me to upgrade to an account with its own mailbox that I could monitor. But I didn’t want another inbox, I only wanted forwarding of all my emails. When I brought up that this was a very flawed project, they pointed out that it was cheap.
I have otherwise been totally happy with Hover, and recommend them without reservation. They were the last line of a long personal journey to find a domain registrar that didn’t suck. I’m gonna stick with them, but I wouldn’t touch their email services if I were you.
I briefly looked into other options for email forwarding and even tried out ImprovMX, which was lovely, but a year of the service was $90. You know what’s less than that? All of my email hosting with Fastmail. And, it turns out, you can handle all your custom domain email forwarding with them for no additional cost. You can even send email from those aliases.
This should be more apparent, hence my blathering on this website.