If Dreamhost gives stellar web service (including ‘unlimited’ domains and ‘unlimited’ users) but sucks at email, then we also need to find the converse:
a company which provides a rock solid email service (for ‘unlimited’ domains and ‘unlimited’ users) at a similar price to what Dreamhost charges for web, i.e. 10 dollars a month.
That rules out any email company which charges per user (or per email address).
For my 10 dollars a month I want:
MX for many domains, each with many email addresses, including a catch-all.
Limits would be a reasonable cap on storage (say 15GB) and a reasonable cap on the number of emails that can be sent per hour.