@fuuko for folks that solely use a web interface to check their mail, I recommend #ProtonMail. For folks that use local clients (#Thunderbird, #mutt, etc.), I suggest #Fastmail, or to investigate the mail offerings of their domain registar. For instance, I think both #DreamHost and #Gandi have decent spam filtering, and no severe outages or anything.
I "require" mutt, and I delete mail rather than archive it, so spam and filtering is the most important for me. #GPG works when I need it. ^_^