I just started the process of moving from gmail to an email on a custom domain through https://www.migadu.com/en/index.html. The setup process was pretty painfree and they provide very detailed setup instructions.
I haven't set my gmail to forward to the new email yet. I've spent the last month or so unsubscribing from a lot of email newsletters. Once I get the mail volume down even further, I'll setup gmail to autoforward and then give out my new email to those who need it.
I haven't yet found a Google Calendar substitute but that's lower priority right now.
Though, my nameservers are on bluehost. My biggest issue is figuring out other aspects of google-tied-ness. For example, everyone has my @gmail email right now. Websites, newsletters, contacts, everybody. Untying that will take a while. Also, I use Inbox for organizing my mail, and I like that a lot. I need to figure out a way to get similar functionality while using a [email protected] domain... either forwarding or something... but then how do I send mail FROM [email protected]?
Mail stuff is so obscure to me, I'd love to sit down and learn it sometime but there's always something "more pressing" for a work project or whatever for me to learn.
EDIT: So, I decided to give it another go. Seems impossible through Inbox, but through gmail I found a thing under settings to "add another email address I own" that lets me input manually the SMTP information that bluehost shows for my email. Might be working, who knows. I'm stuck waiting for google's "verify" email to turn up in my bluehost web inbox.