InboxKit vs Maildoso

InboxKit compared with Maildoso

An architecture choice rather than a price comparison. Maildoso runs its own SMTP infrastructure and sells mailboxes from forty-nine cents with published guidance of about fifteen cold sends a day each; InboxKit sells real provider accounts at about $2.50 that sustain roughly double that. At high volume Maildoso is decisively cheaper per send. At any volume where placement into enterprise Gmail and Outlook tenants is the binding constraint, provider accounts are the safer buy, and InboxKit is the cheapest way to get them.

Maildoso compared with InboxKit

The architecture choice again, with pricing at opposite ends. Maildoso runs its own SMTP infrastructure and sells mailboxes from forty-nine cents with published guidance of about fifteen cold sends a day each. InboxKit sells genuine Google, Microsoft, and Azure accounts from about $2.50 that sustain roughly double that, with InfraGuard monitoring on top. Both ship an API and an MCP server, which is rare here, so the decision comes down to whether provider provenance matters for your recipient base.

InboxKit

Pay-as-you-go against a wallet balance, priced per mailbox per month for Google and Microsoft accounts and per tenant for Azure, with warmup and InfraGuard monitoring as separate add-ons and domains billed separately.

• Professional$39
• Agency$99
• Enterprise$299
• Azure tenant$30
• Add-ons$3

On published prices InboxKit is the cheapest genuine provider-account mailbox in this category, undercutting Primeforge at $4.50 a slot and Premium Inboxes at $3.50, and sitting far below buying Google Workspace or Microsoft 365 seats directly at $6 to $7 each. It is not the cheapest mailbox available, because private SMTP vendors like Maildoso go under a dollar, but that is a different product with lower per-mailbox throughput. The honest comparison at thirty mailboxes is roughly $99 a month here against about $135 at Primeforge and about $105 at Premium Inboxes, before warmup, with the API, the MCP server, and the workspace tooling included rather than gated. Add warmup and InfraGuard and the effective cost roughly doubles, which is the number to use when comparing against vendors that bundle warmup into the sticker price.

Maildoso

Monthly mailbox packages with steeply falling unit cost by volume, plus separate domain registration at a flat annual rate; legacy quarterly bundles that include domains remain listed.

• Thirty mailboxes$75
• Three hundred mailboxes$225
• One thousand mailboxes$499
• Domain registration$12
• Legacy quarterly bundlesFrom $299

Maildoso wins on unit cost and loses on throughput, so model both. At 10,000 emails a month, fifteen sends a day per mailbox implies roughly twenty-two to twenty-five mailboxes, which fits the $75 thirty-mailbox package plus a few domains: cheaper than provider-account infrastructure but not dramatically so, because you are buying nearly twice the mailbox count. At 100,000 a month you need on the order of 220 to 250 mailboxes, which fits comfortably inside the $225 three-hundred package, against roughly $330 to $675 a month for the same volume from Mailforge, Primeforge, or Zapmail. That is the honest shape of it: broadly comparable at low volume, decisively cheaper at high volume, with the open question being whether SMTP mailboxes place as well as real Workspace accounts for your specific recipient base.