This would be my complaint having had a quick look at Fastmail. Their mail client provides only the most basic of email functionality - folders, filters, contac

This would be my complaint having had a quick look at Fastmail. Their mail client provides only the most basic of email functionality - folders, filters, contacts etc. It seems like you're paying a monthly subscription for privacy when you may as well host your own if you don't need any features beyond what IMAP offers as standard.