InboxKit
US-IP Google Workspace and Microsoft 365 mailboxes for cold email, with DNS set up for you and 24+ sequencer integrations, from $2.50 per mailbox a month.
From $2.50/mailbox/mo API
Bottom line
US-IP Google Workspace and Microsoft 365 mailboxes for cold email, with SPF, DKIM and DMARC set up for you and export to 24+ sequencers. One flat rate per mailbox: $3.00 a month, or $2.50 on annual billing, with no plan or minimum.
Stands out for: Each domain gets its own isolated admin panel, so one damaged domain does not drag the others down. A full REST API with webhooks lets agencies provision mailboxes automatically when a new client signs, and an Azure option covers up to 100 mailboxes for $30 a month.
Watch out for: Warmup is not included: it is a $3 per mailbox a month add-on, more than the annual mailbox price itself. The $2.50 rate needs annual billing, and there is no free trial, though you can start with a single mailbox. The 90%+ inbox placement figure is the vendor's own claim.
Overview
InboxKit handles the infrastructure behind cold email. You connect existing domains or buy new ones, create Google Workspace, Microsoft 365 or Azure mailboxes in bulk, and it configures SPF, DKIM and DMARC, enables 2FA and generates app passwords. Every domain sits in its own admin panel, and orders complete automatically in 30 to 120 minutes.
Mailboxes export to 24+ sequencers including Instantly, Smartlead, Apollo, Reply.io and Lemlist, and a REST API with webhooks covers custom workflows. Pricing is one flat rate per mailbox from a prepaid wallet, with unlimited team members and workspaces included. Isolated warmup and the InfraGuard blacklist, DNS and bounce monitoring suite are sold as add-ons.
Who it's for
Best for
- Agency recruiters sending cold email to hiring managers at volume
- Teams already sequencing in Instantly, Smartlead, Lemlist or Apollo
- Teams that want to automate mailbox setup through an API
Not ideal for
- Recruiters sending a handful of emails a day from their own inbox
- Teams that want warmup and sending included in one price
Key features
Google and Microsoft mailboxes. Provision US-IP Google Workspace, Microsoft 365 or Azure mailboxes in bulk, each domain with its own isolated admin panel and 2FA.
Automatic SPF, DKIM and DMARC. DNS authentication is configured for every domain, and app passwords are generated for your sending tool.
REST API and webhooks. Create and manage mailboxes and domains from your own workflows, and export mailboxes to 24+ sequencers including Instantly, Smartlead and Apollo.
Pricing
| Plan | Price | What you get |
|---|---|---|
| Google mailbox | $2.50/mailbox/mo | Annual billing; $2.70 quarterly, $3.00 monthly |
| Microsoft mailbox | $2.50/mailbox/mo | Annual billing; $2.70 quarterly, $3.00 monthly |
| Azure tenant | $30/tenant/mo | Up to 100 mailboxes, same price on every cycle |
InboxKit charges one flat rate per mailbox, with no plans, no minimum and no base fee. Google Workspace and Microsoft 365 mailboxes cost the same: $3.00 a month on monthly billing, $2.70 on quarterly and $2.50 on annual. Azure is billed per tenant at $30 a month for up to 100 mailboxes. Isolated warmup is an add-on at $3 per mailbox a month, and the InfraGuard monitoring add-on has its first month free. You pay from a prepaid wallet. Confirm current terms on the vendor site.
Checked 30 Sep 2026. Vendors change prices without notice.
Is InboxKit expensive?
InboxKit starts at $2.50/mailbox/mo. We list 36 deliverability tools in total. 4 have a free tier, and those with a public price typically start around $10 a month.
- 1 quote-based
- 4 free tier
- 35 public price
Worked out automatically from every deliverability listing, so it updates as the directory changes.
Pros and cons
Pros
- Same price for Google and Microsoft mailboxes
- No plans, slots or minimums
- Full API with webhooks
Cons
- Warmup costs extra
- No free trial
- No sequencer of its own
Integrations
Instantly Smartlead Apollo Reply.io Lemlist Salesforge Plusvibe Google Workspace
What's new at InboxKit
No updates logged yet. Follow InboxKit and we will email you when it announces something new or its starting price changes.
Follow InboxKit
Get an email when InboxKit ships a new feature, posts release notes or changes its starting price. Only when something changes, and you can stop in one click.
How InboxKit compares
See all InboxKit alternatives, with what each one does differently and a head to head for every pairing.
| Tool | Free tier | From | MCP | API | Compare |
|---|---|---|---|---|---|
| InboxKit (this tool) | – | $2.50/mailbox/mo | – | ✓ | |
 Icemail Same $2.50 per mailbox headline without annual billing, though the vendor marks it a limited deal against a listed $3.50. | – | $2.50/mailbox/mo | – | ✓ | Compare |
| | – | $3.50/mailbox/mo | ✓ | ✓ | Compare |
| | – | $39/mo | – | ✓ | Compare |
| | – | $3.30/inbox/mo | – | ✓ | Compare |
Icemail$2.50/mailbox/mo API
Same $2.50 per mailbox headline without annual billing, though the vendor marks it a limited deal against a listed $3.50.
$3.50/mailbox/mo MCP API
Google and Microsoft mailboxes from $3.50, with an MCP server as well as a REST API.
$39/mo API
Automated Google and Microsoft mailbox setup sold as plans from $39/mo rather than a per mailbox wallet.
$3.30/inbox/mo API
Google inboxes from $3.30, with Microsoft Entra domains as its option for scale.
Your next step
Shortlisting InboxKit?
Still deciding? Ask an AI assistant about InboxKit.
ChatGPT (opens in a new tab)Claude (opens in a new tab)Grok (opens in a new tab)