I use fastmail, I love it. I have a catchall and thus can use a different address per service. Leads to sometimes awkward conversations as to why the email address contains the company name in it, but can also be a life saver. For instance, free recently got hacked and all their email db was online. I can just block this email address and not receive the spam.
Fastmail itself is reliable and fast on the web, but I only use it through IMAP anyways. It works perfectly.