Cold Email Infrastructure
Cold email infrastructure providers supply the sending layer underneath an outbound campaign: they register secondary domains, provision Google Workspace, Microsoft 365, or private mailboxes in bulk, write the SPF, DKIM, and DMARC records automatically, and hand the credentials to whichever sequencer you already use.
This category exists because the sending platform and the thing it sends from stopped being the same purchase. A sequencer manages campaigns; somebody still has to buy fifty domains, stand up two hundred mailboxes, authenticate every one of them, and retire the accounts that burn out. Vendors here compete on what kind of mailbox they sell, genuine provider accounts against private SMTP on dedicated IPs, on how much of the DNS and monitoring work disappears, and on how the unit price behaves once the mailbox count runs into the hundreds.
InboxKit
Category LeaderEase of UseOfficial Google, Microsoft, and Azure mailboxes on US IPs, provisioned by API
Zapmail
MomentumPre-warmed Google and Microsoft mailboxes, connected to your sequencer in minutes
Mailforge
InnovationBuy domains and mailboxes in bulk with the DNS already done
Primeforge
Real Google Workspace and Microsoft 365 mailboxes, provisioned in bulk
Maildoso
Best ValuePurpose-built cold email mailboxes from 49 cents a month
Infraforge
Private email infrastructure with dedicated IPs, provisioned in five minutes
Inframail
Unlimited Microsoft inboxes on a dedicated IP, for one flat monthly fee
Mailreef
Your own mail server and dedicated IP, with the inboxes on top included
ScaledMail
Managed cold email infrastructure with deliverability people in a shared Slack channel
Premium Inboxes
Human-configured Google and Microsoft inboxes, delivered in hours with unlimited replacements
Profiles are listed in editorial order. Placement cannot be purchased; see our methodology.