Head to head

InboxKit vs Primeforge

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

Primeforge

$4.50/mailbox/mo

Google Workspace and Microsoft 365 mailboxes for cold email, from $4.50 per mailbox per month billed yearly. 10-slot minimum.

Where Primeforge fits

Teams that want real Google or Microsoft inboxes
Senders using ESP matching for inbox placement
Shops automating setup through the Primeforge API
Buyers already on Salesforge or Mailforge

At a glance

Detail	InboxKit	Primeforge
Starting price	$2.50/mailbox/mo	$4.50/mailbox/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

Primeforge

Stands out: US-IP Google and Microsoft mailboxes so you can match the ESP your prospects use.

Watch out: Minimum 10 mailbox slots. No free trial. Yearly billing is the $4.50 rate; monthly is higher.

Not the right fit for

Buyers who need fewer than 10 mailboxes
Teams that want a free trial before buying slots

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

Primeforge

Real Google and Microsoft mailboxes
REST API included
US IP addresses

10 mailbox slot minimum
No free trial
Empty slots still bill

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

Primeforge

$4.50/mailbox/mo

Mailbox slots $4.50/month billed yearly, 10-slot minimum. 25 slots are $94/month yearly vs $113/month monthly..com domains $14/year. API included. No free trial. Cancel anytime. Each Forge product is a separate subscription. Confirm current terms on the vendor site.

Checked 19 Sep 2026

Common questions

Is InboxKit cheaper than Primeforge?

InboxKit starts lower, at $2.50/mailbox/mo against $4.50/mailbox/mo for Primeforge. 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 Primeforge for free?

Neither carries a free tier on our listing.

Not the pair you wanted?

All InboxKit alternatives All Primeforge alternatives Every Deliverability tool

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