What the $99 buys
ZeroBounce sells two ways. Pay as you go starts at $39 for 2,000 credits, its minimum purchase. The subscription, ZeroBounce ONE, starts at $99 a month for 10,000 credits and bundles a deliverability suite: activity data, email warmup, inbox placement tests, blacklist and DMARC monitoring, an email finder, and credits that don't expire while you stay subscribed.
That's a reasonable package for a team whose job is deliverability. For a founder cleaning a newsletter list or a developer checking sign-ups, most of it goes unused. Emailfortify sells only the verification part: 5,000 checks for $9 a month, or 25,000 for $29. That's $1.80 and $1.16 per 1,000 addresses, against ZeroBounce's $19.50 pay as you go and $9.90 on ONE.
What ZeroBounce can tell you that we can't
Most of what a verifier does is the same everywhere: check the syntax, look up the domain's mail servers, ask the server whether the mailbox exists, then test a random address to see whether the domain accepts everything. ZeroBounce adds statuses that come from data, not from the mail server:
- spamtrap: addresses it believes are spam traps, which can get a sender blocklisted.
- abuse: people known to mark mail as spam.
- do_not_mail: a group covering disposable, role-based and "toxic" addresses, among others.
Emailfortify has no list of known traps or complainers, and we'd rather say so than imply otherwise. What we do give you is the reason behind each verdict in words, such as "the mail server says this mailbox doesn't exist" or "the domain accepts mail for every address, so this mailbox can't be confirmed", along with the mail server's own reply code when it gave one.
Unknown results, and Outlook
An unknown result means the mail server didn't give a clear answer: it was down, asked to try later, or refuses to be checked. Neither of us charges for those: ZeroBounce's pricing FAQ says it never does, and Emailfortify puts the credit back.
Free doesn't make an unknown useful, though, and right now we return more of them for one group of addresses. Microsoft's consumer mail servers (Outlook.com, Hotmail, Live) refuse checks from our server's address, so those come back unknown. If a large share of your list is on Hotmail or Outlook.com, ZeroBounce will give you more answers. Here's what you can expect from each big provider with us:
Free tools on both sides
Both sites have free tools. Ours check the DNS behind your own sending: an SPF checker that counts every DNS lookup through your includes against the limit of 10, a DKIM checker that tries the selectors used by Google, Microsoft 365, Amazon SES and others, a DMARC checker, an MX lookup and a one-page domain health report. None needs an account.
At a glance
From ZeroBounce's own pricing and help pages, checked October 19, 2026.
Where ZeroBounce is the better choice
- Spam traps and complainers. If your list has an unknown history, ZeroBounce's spamtrap and abuse statuses can catch addresses no mailbox check will.
- Outlook and Hotmail. While Microsoft refuses our checks, those addresses come back unknown with us.
- A deliverability suite. Warmup, inbox placement tests and monitoring in the same account.
- Credits that last. On ONE, unused credits don't expire. Ours reset every month.
NeverBounce alternative: the same checks for a fraction of the price per address
Kickbox alternative: a monthly plan instead of buying in batches