Line by line
| Feature | Inboxkit | Instantly |
|---|---|---|
| Mailboxes | Official, paid Google Workspace and Microsoft 365, plus Azure | Done-for-you Google accounts; AirMail is Instantly’s own SMTP |
| Claude Code / Codex (MCP) | Remote MCP server, connects to Claude Code and Codex | Hosted MCP server; API on all plans |
| Admin panel access | Complete admin panel access for every domain | Kept by Instantly, not transferred |
| Google price | $3 a mailbox, or $2.50 annual | $5 an account a month, plus $15 a domain a year |
| Microsoft | Microsoft 365 at $3, plus Azure at $30 a tenant for up to 100 | No done-for-you option listed |
| Domains | Buy domains or connect your own | Bought through Instantly, .com or .org, up to 5 accounts each |
| Where they work | One-click export to 24+ sequencers, Instantly included | Configured for use inside Instantly only |
| Switching sequencers | One-click export to any of 24+ | Terms give no right to transfer, port or migrate them |
| Pre-warmed | Pre-warmed mailboxes, live in hours | $10 an account a month, in batches of 5 |
| Warmup | 14-day warmup on an isolated network, a $3 add-on | On automatically; included in every Instantly plan |
| Monitoring (add-on) | InfraGuard every six hours: blacklists, DNS, bounces, placement, auto-pause | Deliverability tests and DNS checks; no automatic schedule stated |
Competitor details from public pages, checked 19 Oct 2026. Sources: Instantly email accounts (instantly.ai); Instantly pricing (instantly.ai); Instantly done-for-you setup (help.instantly.ai); Instantly pre-warmed accounts (help.instantly.ai); Instantly AirMail accounts (help.instantly.ai); Instantly email accounts dashboard (help.instantly.ai); Instantly terms (instantly.ai); Instantly MCP server (developer.instantly.ai); Inboxkit pricing.
Competitor offers can change after that date. Trademarks belong to their owners.
Prices at common volumes
| Mailboxes | Inboxkit, monthly | Inboxkit, annual | Instantly |
|---|---|---|---|
| 20mailboxesInstantly also bills at least 4 domains at $15 a year | Inboxkit, monthly$60 | Inboxkit, annual$50 | Instantly$100 |
| 100mailboxesInstantly also bills at least 20 domains at $15 a year | Inboxkit, monthly$300 | Inboxkit, annual$250 | Instantly$500 |
| 1,000mailboxesInstantly also bills at least 200 domains at $15 a year | Inboxkit, monthly$3,000 | Inboxkit, annual$2,500 | Instantly$5,000 |
Instantly turns on warmup for done-for-you accounts automatically, and every Instantly plan includes warmup. Ours is a $3 add-on.
Mailboxes only. Instantly adds at least one $15 domain a year for every 5 done-for-you accounts. Sending from Instantly needs an Instantly plan with either option.
Instantly mailbox pricing against Inboxkit
Instantly’s done-for-you Google accounts cost $5 an account a month. Each sits on a domain bought through Instantly, at $15 a year for up to 5 accounts. Pre-warmed accounts cost $10 a month, sold in batches of 5.
Inboxkit charges $3 a mailbox on monthly billing, or $2.50 on annual. Google and Microsoft cost the same, with no plan and no minimum.
At 1,000 Google mailboxes, Instantly’s accounts cost $5,000 a month and Inboxkit costs $3,000 at today’s published rate. Both figures are mailboxes only. Instantly also bills at least 200 domains at $15 a year.
Google, Microsoft and Azure mailboxes
Instantly provisions Google accounts and adds them to your Instantly workspace. It lists no done-for-you Microsoft or Outlook accounts. Its third option, AirMail, is Instantly’s own private SMTP product at $4 an account a month.
Inboxkit sells official, paid Google Workspace and Microsoft 365 mailboxes at the same $3. For Microsoft volume, one Azure tenant holds up to 100 mailboxes for $30 a month. Pre-warmed mailboxes are live in hours.
Instantly domains, admin access and ownership
Done-for-you accounts sit on new domains that Instantly buys, in .com or .org only. Instantly keeps domain ownership and admin access and does not transfer them. Its terms give no right to transfer, port or migrate the accounts.
On Inboxkit you buy domains or connect your own in one click. You get complete admin panel access for every domain. SPF, DKIM and DMARC are set automatically, and orders complete in 30 to 120 minutes.
Instantly warmup and monitoring
Instantly turns warmup on once a done-for-you account is set up, and every Instantly plan includes warmup. Its dashboard has inbox placement tests and DNS checks. Instantly states no automatic check schedule for done-for-you accounts.
Inboxkit’s warmup is a $3 add-on that runs for 14 days on an isolated network. InfraGuard checks blacklists, DNS, bounces and inbox placement every six hours, with alerts and auto-pause. It is also an add-on, and its first month is free.
Instantly API and MCP server
Every Instantly plan includes API access. Instantly also runs a hosted MCP server at mcp.instantly.ai for its V2 API.
Every Inboxkit account gets the full REST API, with 119 endpoints and webhooks. Connect Claude Code or Codex to Inboxkit’s remote MCP server to run your mailbox work from an agent.
Using Inboxkit mailboxes in Instantly
Inboxkit mailboxes export to Instantly in one click. The same mailboxes also export to Smartlead and any of 24+ sequencers, so you can change tools later.
Instantly’s done-for-you accounts are configured for use inside Instantly only. Whichever mailboxes you use, sending from Instantly needs an active Outbound plan. Growth starts at $47 a month.
Move your sending mailboxes to Inboxkit
Create a free account
Pay only for the mailboxes you add. No plan to pick first.
Buy or connect domains
Then add Google Workspace, Microsoft 365 or Azure mailboxes on them.
Export to your sequencer
One click to 24+ sequencers, including Smartlead and Instantly.
Run both side by side
Keep Instantly running while the new mailboxes warm up.
Questions about Instantly
Is Inboxkit cheaper than Instantly’s done-for-you accounts?
Per Google mailbox, yes: $3 here against $5 for an Instantly done-for-you account. At 1,000 mailboxes that is $3,000 against $5,000 a month, before Instantly’s $15 a year for each domain.
How does Instantly mailbox pricing work?
Done-for-you Google accounts are $5 a month each. Each domain costs $15 a year and holds up to 5 accounts. Pre-warmed accounts are $10 a month in batches of 5. AirMail SMTP accounts are $4.
Does Instantly offer Microsoft or Azure mailboxes?
Instantly lists no done-for-you Microsoft or Outlook accounts; AirMail is its own SMTP product. Inboxkit sells Microsoft 365 mailboxes at $3. One Azure tenant holds up to 100 for $30 a month.
Do Inboxkit mailboxes work with Instantly?
Yes. Export them to Instantly in one click. The same mailboxes also export to Smartlead and any of 24+ sequencers.
Can I move Instantly’s done-for-you accounts to another tool?
Instantly’s help center says they are configured for use inside Instantly only. Its terms give no right to transfer, port or migrate them. Inboxkit mailboxes export to any of 24+ sequencers.
Does Instantly have an API and an MCP server?
Yes. Every Instantly plan includes API access, and Instantly runs a hosted MCP server. Inboxkit includes the REST API and a remote MCP server on every account.
How do I move from Instantly’s accounts to Inboxkit?
Open a free account, buy or connect domains, and add mailboxes. Export them to Instantly in one click. Keep your old accounts sending until your campaigns have moved.
Open a free account
$3 a mailbox, no minimum. Google Workspace, Microsoft 365 and Azure.
