Head to head

InboxKit vs Zapmail

Same facts, side by side: starting price, free tier, MCP, API and what each one is actually built for.

InboxKit

$2.50/mailbox/mo

Google Workspace and Microsoft 365 mailboxes from $2.50 per mailbox per month on yearly wallet billing. REST API included.

Where InboxKit fits

Agencies that want Google and Microsoft at the same rate
Teams billing mailboxes from a wallet with no minimum
Senders connecting Instantly, SmartLead, or Lemlist
Shops that need REST API and webhooks

Zapmail

$39/mo

Google Workspace and Microsoft 365 mailboxes for cold email. Starter is $39/mo for 10 Google mailboxes.

Where Zapmail fits

Freelancers starting with 10 Google inboxes
Agencies that want pre-warmed Workspace accounts
Teams exporting to Instantly or Smartlead
Senders who need one domain per workspace

At a glance

Detail	InboxKit	Zapmail
Starting price	$2.50/mailbox/mo	$39/mo
Free tier	–No	–No
MCP server	–No	–No
Public API	✓Yes	✓Yes
Listed under	Deliverability	Deliverability

Where they pull apart

InboxKit

Stands out: Same $2.50 yearly rate for Google and Microsoft, with no slot minimum on wallet billing.

Watch out: The $2.50 figure is yearly Enterprise wallet billing. Warmup is $3 per mailbox extra. A FAQ still cites a $39 Professional pack.

Not the right fit for

Buyers who want warmup in the $2.50 rate
Teams that need a traditional free trial

Zapmail

Stands out: Pre-warmed US/EU Google and Microsoft mailboxes with automated DNS and OAuth export to sequencers.

Watch out: API access starts on Pro at $299/mo. Extra Google mailboxes cost $3.50 each on Starter.

Not the right fit for

Buyers who need API access on Starter
Teams that want dedicated SMTP IPs they control

Pros and cons

InboxKit

$2.50/mailbox/mo yearly, no minimum
Google and Microsoft same price
REST API and webhooks included

Warmup is $3/mailbox extra
No traditional free trial
FAQ still cites a $39 pack

Zapmail

Starter $39/mo for 10 mailboxes
Pre-warmed Google and Microsoft
OAuth export to major sequencers

API only on Pro at $299/mo
No published free trial
Extra Starter mailboxes are $3.50

What each one costs

InboxKit

$2.50/mailbox/mo

Google and Microsoft mailboxes $2.50/mailbox/month on yearly wallet billing, no minimum. Azure tenants $30/tenant/month. Warmup add-on $3/mailbox/month. FAQ also cites Professional from $39/month for 10 mailboxes; the printed wallet cards are $2.50. API included. No traditional free trial. Confirm current terms on the vendor site.

Checked 19 Sep 2026

Zapmail

$39/mo

Starter is $39/month for 10 Google mailboxes, extra mailboxes $3.50. Growth is $99/month for 30, extra $3.25. Pro is $299/month for 100, extra $3.00, and includes API access. All plans billed monthly. Pre-warmed Google and Microsoft accounts. No free trial. Confirm current terms on the vendor site.

Checked 19 Sep 2026

Common questions

Is InboxKit cheaper than Zapmail?

InboxKit starts lower, at $2.50/mailbox/mo against $39/mo for Zapmail. That is the entry plan on each side, so the real number depends on seats and the tier you land on.

Can you try InboxKit or Zapmail for free?

Neither carries a free tier on our listing.

Not the pair you wanted?

All InboxKit alternatives All Zapmail alternatives Every Deliverability tool

Editorial listings, never paid rankings. Prices checked 19 Sep 2026. Confirm current terms on the vendor site. Spot an error?