Maildoso vs Premium Inboxes (2026): which should you pick?

Pick Maildoso if

• Fits if you need 30 or more mailboxes for an outbound team
• Works for senders who already run Instantly or Smartlead

Look elsewhere if

• Skip it if you need just a few mailboxes, since 30 is the smallest block
• Not for you if you want a trial or a discount, because neither exists
• Watch out: domains cost extra, $15 a year or $11.90 a month pre-warmed
• Tight if you want volume per mailbox: 15 cold emails a day each

Pick Premium Inboxes if

• Fits if you want 30 or more inboxes set up and handed over
• Works for agencies that already have a sequencer

Look elsewhere if

• Tight if you need fewer than 30 inboxes, because both plans have a 30-inbox minimum
• Skip it if you want a trial, as there is none
• Watch out: domains are not in the price, so you buy them yourself
• Pricey if you want an account manager, a Slack channel or 24-hour monitoring, since all three need the $4.50 tier

Maildoso

• Each mailbox sends at most 15 cold emails and 80 warm-up emails a day, and new mailboxes still need about 14 days of warm-up unless they sit on pre-warmed domains.
• Domains are not included in monthly plans: registration is $15 a year and a pre-warmed domain is $11.90 a month.
• Quarterly plans with domains included are labeled legacy on the pricing page; the monthly blocks are the current plans.
• Subscriptions are canceled through support chat or email, and the page says it has a no-discount policy with no promotions.

Premium Inboxes

• You supply the domains; the site does not list domain purchase in the price.
• Both plans start with a minimum order of 30 inboxes.
• It provides mailboxes only; you need a separate sequencer to send campaigns.
• Account manager, Slack channel and 24-hour monitoring come only with the $4.50 tier.

Maildoso

Mailboxes built for outbound

Dedicated mailboxes on the vendor's own servers and IPs, with IP rotation and automatic replacement of IPs that stop working.

Automatic DNS setup

SPF, DKIM and DMARC records are configured when you register mailboxes under a domain bought or connected through the dashboard.

Self-healing and health scores

Burned-out mailboxes are disconnected from campaigns for 14 days, and inbox placement tests run every 3 days with a health score per mailbox.

Sequencer export

Mailboxes can be exported to outreach platforms; Instantly, Smartlead and EmailBizon sync with one click, and the vendor says 9 sequencers are supported.

API and MCP server

Register domains, create mailboxes and push them to a sequencer from code or from an AI assistant such as Claude.

Pre-warmed domains

Domains warmed in advance, each holding up to 50 mailboxes, so new mailboxes can start sending without the usual 14-day wait.

Premium Inboxes

Google Workspace and Microsoft 365

Inboxes are business accounts on either provider, and the pricing page has a toggle for each.

Technical setup handled

The vendor says it configures DNS with SPF, DKIM and DMARC, creates the inboxes, sets up profiles and enables warmup.

Sequencer upload

Inboxes are uploaded directly to the sequencer. The site lists Instantly, Smartlead, Apollo, Lemlist, Reply.io and Bison.

Unlimited replacement inboxes

Both plans include replacement inboxes when one is lost or flagged, with a priority queue on the higher plan.

Slack support channel

The higher plan adds a dedicated Slack channel and account manager, and the site says the founder joins customer channels.

Infrastructure calculator

A calculator turns a daily send volume into a number of inboxes, domains and a monthly cost.

Maildoso

• 30 mailboxes$75

  per month for 30 mailboxes ($2.50 each)

  Aimed at early-stage teams. Up to 15 cold emails a day per mailbox, plus the features every plan includes.

• 300 mailboxes$225

  per month for 300 mailboxes ($0.75 each)

  Aimed at expanding teams. Same features and 15-a-day limit per mailbox as the smaller block.

• 1,000 mailboxes$499

  per month for 1,000 mailboxes ($0.49 each)

  Aimed at large-scale campaigns. Same features and per-mailbox limit.

Premium Inboxes

• Start Up$3.50

  per inbox / month, for 1 to 249 inboxes

  No monthly commitment, dashboard, full technical setup, upload to your sequencer and unlimited replacement inboxes. Orders start at 30 inboxes.

• Insured Infrastructure$4.50

  per inbox / month

  Adds a dedicated account manager and Slack channel, advanced analytics, priority support and build queue, and 24-hour monitoring.