InboxKit vs Maildoso: Which is Better?

InboxKit vs Maildoso

Feature	InboxKit	Maildoso
Pricing
Price per Mailbox	$2.50/mo Flat rate for all mailbox types (Google Workspace, Microsoft 365, Azure)	$1.90-$2.50/mo SMTP from $1.90, Combo (SMTP+GW) from $2-$3/mo
Infrastructure
Mailbox Types	GWS + M365 + Azure Google Workspace, Microsoft 365, and Azure all available	SMTP + Combo SMTP mailboxes or Combo (SMTP plus Google Workspace)
IP Location	US IPs US-based IP addresses for all mailboxes	Not specified IP location varies by mailbox type
DNS Automation	Full auto SPF, DKIM, DMARC, and MX records set up automatically	Auto DNS Automated DNS configuration included
Deliverability
Inbox Placement Rate	95% claimed 95% inbox placement rate across all mailbox types	Not published No public inbox placement rate claim
Built-in Warmup	Yes Email warmup built into the infrastructure platform	No Warmup must come from your sending tool
Inbox Placement Testing	Yes Test whether emails land in inbox or spam	No Not available, use your sending platform
Email Verifier	Yes Built-in email verification tool	No Not available natively
Blacklist Checker	Yes Monitor IPs and domains against blacklists	No Not available natively
Scale
Scale Track Record	Enterprise clients Trusted by 11x, Zendesk, PwC, Merck	400K+ mailboxes 400,000+ mailboxes managed, 10M+ emails/day
Social Proof
G2 Rating	Not listed No G2 rating published	4.7 (159 reviews) 4.7 out of 5 from 159 verified G2 reviews
Automation
API Access	Yes API for automated mailbox provisioning	Yes + MCP API and MCP support for automation

Infrastructure and Mailbox Types

The biggest difference between InboxKit and Maildoso is mailbox diversity. InboxKit supports Google Workspace, Microsoft 365, and Azure mailboxes under one roof. This flexibility lets you test which provider delivers best for your domain and audience.

Maildoso focuses on SMTP mailboxes with a Combo tier that adds Google Workspace. For cold email, Google Workspace mailboxes generally have higher inbox placement rates than SMTP. InboxKit gives you that option from day one.

Maildoso compensates with lower pricing and proven scale, managing 400,000+ mailboxes and processing 10 million+ emails per day.

Deliverability Tools

InboxKit bundles a complete deliverability stack into the infrastructure layer: warmup, inbox placement testing, email verification, and blacklist monitoring. This is unique among infrastructure providers. Most competitors (including Maildoso) leave deliverability to your sending tool.

Maildoso does not include warmup, verification, or placement testing. You will need those from SendKit or another sending platform. For teams that already use SendKit (which includes all of those tools), this is not a problem.

For teams that want deliverability monitoring at the infrastructure level, InboxKit is the only choice.

Pricing at Scale

At 100 mailboxes, InboxKit costs $250 per month ($2.50 x 100). Maildoso SMTP costs $190 to $250 per month ($1.90-$2.50 x 100). The Maildoso Combo tier with Google Workspace costs $200 to $300 per month.

The $0 to $60 difference per month is small at 100 mailboxes. Factor in that InboxKit includes warmup and deliverability tools that Maildoso does not, and the real cost gap narrows further. At 200+ mailboxes the savings from Maildoso become more meaningful, especially for agencies managing multiple client accounts.

Which One Should You Choose

Choose InboxKit if you want a single provider that handles mailbox provisioning, DNS, warmup, and deliverability monitoring. The $2.50 per mailbox price is fair when you factor in the built-in tools you would otherwise pay for separately. InboxKit also gives you the most mailbox type flexibility with Google Workspace, Microsoft 365, and Azure.

Choose Maildoso if raw cost per mailbox is your priority and you already use SendKit or another sending tool that handles warmup and deliverability. Maildoso is proven at scale with 400K+ mailboxes and has the strongest G2 reviews in this category. Both providers connect to SendKit for campaign management, sequences, and AI warmup.