Two names that come up in every cold email infrastructure shortlist, usually right after someone has been burned by a shared-inbox provider. Both sell inboxes at scale with DNS handled for you. Both are reasonable. And the comparison between them is less useful than the questions neither marketing page answers.
What actually differs
| Question | Why it decides the purchase |
|---|---|
| Real Google / M365 tenants, or provider SMTP? | Determines inherent sender trust and how replies thread. The single biggest deliverability variable. |
| Who owns the accounts? | If the tenant is the provider’s, leaving means rebuilding reputation from zero. |
| Who registers the domains? | Domain age and reputation are assets. Losing them on cancellation is an exit cost nobody quotes you. |
| Dedicated IP, or shared? | Shared means other senders influence your inbox placement invisibly. |
| Provisioning at volume | Same-day for 10 is easy. Ask what happens when you order 80. |
| Bulk DNS updates | At 40+ domains, editing SPF records one at a time is where silent failures come from. |
| Price per inbox per month | At 60 inboxes, a $2 difference is $1,440 a year. |
Maildoso, in short
Positioned around fast setup and its own inbox infrastructure, with DNS configuration handled and pricing that undercuts buying Google seats directly. Teams generally like the speed to first send.
The question to ask: whether the inboxes are genuine Google or Microsoft tenants or Maildoso-operated mailboxes, because that determines both deliverability behaviour and what you keep if you leave.
Mailscale, in short
Similar territory, oriented toward volume and agency use, with bulk provisioning and domain management as the main pitch. Also competes primarily on price against buying seats direct.
The question to ask: the same one, plus what provisioning actually looks like when you order 80 inboxes at once rather than 8.
The question that matters more than either
Both of these are answers to “how do I get a lot of inboxes cheaply”. That is the right question at 30 inboxes. At 100 it is the wrong one, because the real cost driver stops being the per-inbox rate and becomes reputation risk.
When 100 mailboxes share infrastructure, one bad list or one aggressive campaign degrades placement across all of them, and you will not be able to prove it. That is not a hypothetical, it is the most common reason teams churn from shared-inbox providers, and it usually shows up as “our open rates dropped and nobody knows why”.
Dedicated IPs solve it. Every mailbox on Mailboundry gets its own IP, so a problem on one campaign is contained to one IP, and your deliverability becomes something you can actually debug. Pricing starts at $2 per mailbox per month with the IP included, on monthly, quarterly or annual billing.
If you want real Google and Microsoft mailboxes
Sometimes the right answer is genuinely the seat-based one, enterprise recipients, lower volume, reply quality over raw send count. In that case buy real tenants, not lookalikes. Outboundry provisions Google Workspace and Microsoft 365 mailboxes at $4 per mailbox per month on monthly billing, with SPF, DKIM, DMARC and MX published automatically and bulk updates across every domain afterwards. Domains are purchased in-app up to $14 per TLD and registered to you.
A short buying checklist
- Ask, in writing, whether the mailboxes are real Google Workspace or Microsoft 365 tenants.
- Ask who the registrant is on the domains, and what the transfer process is if you cancel.
- Ask whether IPs are dedicated or shared, and what an additional IP costs.
- Order a small batch first and time provisioning. Then ask what changes at 10x that volume.
- Price the full stack, inboxes plus sequencer plus warmup plus data, not the inbox line alone.
Answer those five and the Maildoso-versus-Mailscale question usually answers itself, or stops being the relevant question.
Next: private infrastructure alternatives compared, or Google and M365 mailbox providers from $4.
Frequently asked questions
What is the difference between Maildoso and Mailscale?
Both provision cold email inboxes at scale with DNS handled. The differences are in mailbox type, whether you own the underlying accounts and domains, provisioning speed at volume and price per inbox. Ask each provider directly whether the accounts are real Google or Microsoft tenants and whether you can take them with you.
Are these real Google Workspace mailboxes?
It varies by provider and by plan, which is precisely why you should ask. Some providers sell genuine Workspace or Microsoft 365 tenants, others sell their own SMTP mailboxes that look similar in a sequencer but behave differently in filtering and reply threading.
Do I own the domains I buy through an inbox provider?
Not always. Some providers register domains under their own account, which means leaving costs you the domain reputation you spent months building. Confirm registrar ownership and transfer terms before you buy at volume.
How many inboxes do I need?
Divide target daily sends by 30 to 50 per mailbox, then add about 30% headroom for warmup and rotation. For 1,000 sends a day that is roughly 20 to 33 mailboxes, and you should buy closer to 40.
What is the best Maildoso or Mailscale alternative?
If you want real Google and Microsoft mailboxes, compare on price per seat and ownership terms. If your volume justifies it, private infrastructure with a dedicated IP per mailbox is cheaper per send and gives you reputation isolation neither shared-inbox provider can offer.