Email Infrastructure & Inboxes

Premium Inboxes provisions official Google Workspace and Microsoft 365 mailboxes with manual DNS setup, US IPs, and same-day delivery for cold outreach teams.

Elastic Email pairs marketing campaigns and automation with an SMTP relay and developer API for transactional sending, from $29/month for 2,500 contacts.

Maildoso sells cheap SMTP and Google Workspace mailboxes for cold email, from $0.49 to $2.50 each, but domains, warmup, and DNS control cost extra.

Puzzle Inbox sells Outlook 365 mailboxes from $0.35 and Google Workspace from $3, with real Trustpilot complaints about deliverability and cancellation.

Inboxing provisions Microsoft-based cold email inboxes in bulk, priced per domain with volume tiers, automated DNS setup, and full API access.

MailMonitor is a deliverability service offering inbox placement audits, real-time reputation tracking, and expert remediation, from $475 one-time.

Primeforge sells real Google Workspace and Microsoft 365 mailboxes for cold email outreach with automated DNS setup — warmup and monitoring cost extra.

Slicey is a managed cold email infrastructure service: pre-warmed Google and Microsoft inboxes set up for you, with deliverability monitoring and swaps.