Buy from Zapmail directly if you need more than about 10 mailboxes. Buy inside Smartlead if you need a handful and want everything in one bill. Smartlead's own pricing page lists its Google mailboxes and one of its Outlook options as "Powered by Zapmail", so the mailbox underneath is often the same. The difference is price and packaging: Smartlead charges $4.50 per mailbox a month with no plan minimum, while Zapmail's plans work out to $2.99 to $3.90 per mailbox but start at $39 a month for 10.
Prices below come from smartlead.ai/pricing and zapmail.ai, checked on October 24, 2026.
Per-mailbox prices
Smartlead SmartSenders
| Mailbox type | Provider behind it | Per mailbox a month | Per domain a year |
|---|---|---|---|
| Google, fresh | Zapmail | $4.50 | $13 |
| Google with admin access | Zapmail | $4.50 | $13 |
| Outlook, fresh | Zapmail | $4.50 | $13 |
| Outlook, fresh | InfraInbox | $5.00 | $16 |
| Google or Outlook, pre-warmed | Zapmail | $9.00 | $18 |
| SMTP | Mailreef | $3.99 | $19 |
| SMTP | AeroSend | $4.20 | $13 |
SmartSenders mailboxes are bought inside Smartlead and connect to your Smartlead campaigns. Smartlead's sending plans are separate: Base starts at $39 a month ($32 billed yearly), and every plan includes unlimited email accounts.
Zapmail
| Plan | Price | Mailboxes included | Extra mailboxes |
|---|---|---|---|
| Starter | $39/month | 10 | $3.50 each |
| Growth | $99/month | 30 | $3.25 each |
| Pro | $299/month | 100 | $3.00 each |
Zapmail mailboxes can be Google or Microsoft under one plan and export to Smartlead, Instantly, lemlist and 50+ other sending tools. Yearly billing is cheaper. Domains are a separate cost.
What each costs at 10, 30 and 100 mailboxes
Monthly mailbox cost on monthly billing, before domains.
| Mailboxes | Smartlead SmartSenders (Google) | Zapmail | Cheaper |
|---|---|---|---|
| 5 | $22.50 | $39 (Starter, 10 included) | Smartlead |
| 10 | $45 | $39 (Starter) | Zapmail, slightly |
| 30 | $135 | $99 (Growth) | Zapmail |
| 100 | $450 | $299 (Pro) | Zapmail, by $151 a month |
At 2 to 3 mailboxes per domain, 30 mailboxes need 10 to 15 domains. Smartlead lists those at $13 a domain a year. Our guide on how many mailboxes per domain explains the 2 to 3 limit.
What else differs
- One vendor or two. SmartSenders keeps mailboxes, sending and billing in Smartlead. Zapmail is a second account, but its mailboxes can move to another sequencer if you ever leave Smartlead.
- Pre-warmed mailboxes. Smartlead lists Zapmail-powered pre-warmed mailboxes at $9 a month, double the fresh price. Worth it only if a campaign has a fixed start date. Otherwise, see how long it takes to warm up a new email address.
- Admin access. Smartlead offers a Google option "with Admin Access" at the same price. Ask either vendor who owns the Google Workspace organization before you commit.
- Extras. Zapmail plans include deliverability test credits, aged domains for sale and bulk DNS management. Smartlead adds its own deliverability tools and placement tests as separate plans.
The ownership question
In an r/Coldemailing thread asking "Inbox kit? Zapmail? Mail forge? Smartleads directly?", the most detailed reply made one point above price: if you don't own the underlying Workspace organization, your sending history stays behind when you leave. Six months of sending reputation is worth more than a dollar per mailbox. Ask whether you can take over the Google or Microsoft tenant, and how, before buying from any reseller. Our Zapmail review covers a reviewer's complaint about exactly this.
The same reply questioned the dedicated IP the poster was paying for at 2,500 emails a week. At that volume a clean shared setup often performs about the same.
Test before you move everything
Several replies in that thread gave the same advice: keep your best-performing mailboxes where they are, buy a small batch from the new provider, and compare reply, bounce and inbox placement rates for a couple of weeks. Deliverability between providers varies by niche and changes over time, so no review can tell you how your own campaigns will do. List quality, targeting, volume and copy usually matter more than where the mailbox came from. Our Instantly vs Smartlead deliverability comparison covers the sending side.
Which to buy from
- Under 10 mailboxes, already on Smartlead: SmartSenders. No plan minimum and one bill.
- 10 or more mailboxes: Zapmail directly. Same provider, lower price per mailbox, and portable to other sequencers.
- Not on Smartlead: Zapmail, since SmartSenders only makes sense inside Smartlead.
- Need control of the tenant: confirm ownership terms in writing with either vendor, or buy Google Workspace directly.
Mailboxes are the cheapest line in a cold email budget. Bookings depend on the list, the offer and the copy that go through them. Our guide on how to increase cold email reply rate covers all three. If you want the whole system built and run, that is what KomsGro's B2B cold outbound agency does.