We run SmarterMail for service for clients housed on our web services --
SmarterMail's new SpamFoo is showing quite a bit of promise based on our testing over the last couple days in regards to the spam wars.
We are not recommending ANY major cloud providers due to privacy issues and the continued monetization of everyone's data whether they like it or not, and the continual dark patterns when it comes to trying to opt-out of those privacy invasions they market as "tools"...
That said, if you need a host for those domains, we have options available. DMs are open --
MailEnable survivor / convert --