Inboxkit
Running in productionInbox Provider
Domains and cold email inboxes provisioned in bulk through an API.
The verdict
We run thousands of secondary domains through Inboxkit. The API is the reason: you can provision domains, inboxes, and DNS in bulk without clicking through a dashboard two thousand times. The DNS layer has sharp edges, apex CNAMEs get silently dropped and domain forwarding defaults to on, so script your setup and verify records after. Once running, it is boring in the good way.
