What exactly is a carrier-grade email provider?
Re:I can no longer recommend MailChimp
by CodeWriter23 on Thursday November 02, 2017 @05:15AM
(#15608884)
ISPs/free email at scale (Gmail, etc). Think billions of messages per day. Or where the majority of any audience of an email list receives their email.
In the world of carrier-grade email providers, they outsource spam scoring to one (or more) of a selection of about 3 vendors (Symantec, CloudMark come to mind). These systems also score against the sending domain, among a number of other factors. Source: my best friend is a lead engineer at a carrier-grade email provider.
And playing whack-a-mole with changing sending domains is ill advised as that will lose the benefit of any whitelisting occurring client side.