I’ve been using Fastmail for the last couple of years.
Their email service puts privacy at the forefront of what they do, at a reasonable price and with custom domains available, too.
As well as supporting wildcard email addresses, they also provide free masked email addresses – perfect for signing up to newsletters and websites you don’t want having your personal or business email address.
This is no real surprise. I’ve been working on WordPress-powered websites for over a decade, and it’s my go-to in most circumstances.