Email Verification & Deliverability

Our top three email verification and deliverability tools

DeBounce comes first: for most small senders the first fix is removing addresses that bounce, and its packs start at $15 for 5,000 checks that never expire. Warmup Inbox is second for cold emailers warming new mailboxes, at $15 an inbox a month billed yearly. GlockApps is third for testing placement and reading DMARC reports, free up to 10,000 DMARC messages a month. Warmy narrowly missed: it warms up, checks lists and monitors DMARC on every plan, but starts at $49 a month, rising with volume. ZeroBounce's ONE plan covers all three jobs at $79 a month billed yearly, for one DMARC domain.

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   First: DeBounce

   Free trial · from $15 one-time

   For: Most small senders cleaning a list

   DeBounce removes addresses that would bounce before you send: upload a file or import a list from Mailchimp, HubSpot, Klaviyo or ActiveCampaign, with duplicates removed free, or check sign-ups as they happen through the API, a JavaScript widget or a WordPress plugin. Credits never expire and come in packs of $15 for 5,000, $25 for 10,000 or $135 for 100,000, after 100 free credits with no card. Know the limits: catch-all checks cost 10 credits an address, monthly list rechecks cost twice the list size in credits, and it does not warm up inboxes, test placement or manage DMARC.

   DeBounce pricing and details
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   Second: Warmup Inbox

   Free trial · from $15/mo

   For: Cold emailers warming new inboxes

   Warmup Inbox builds a new mailbox's reputation by trading emails with more than 30,000 real inboxes, which reply to up to 25% of them on Basic, and shows whether warm-up mail lands in spam or a tab. It works with Gmail, Outlook, Microsoft 365 and Zoho Mail. Basic is $15 an inbox a month billed yearly ($19 monthly) for 75 warm-up messages a day, after a 7-day trial with no card. It is second because it serves cold emailers more than every sender: the cost grows with each inbox, language and SendGrid or Amazon SES warm-up need Pro at $49, and it does not clean lists or manage DMARC.

   Warmup Inbox pricing and details
3. 3

   Third: GlockApps

   Free plan · from $59/mo

   For: Senders testing placement and reading DMARC reports

   GlockApps shows where an email lands before it goes out: send it to its seed addresses and it reports inbox, spam or tab at Gmail, Yahoo, Outlook and others, with SpamAssassin scores, authentication checks and 50+ blocklists. Its DMARC Analyzer reads reports for unlimited domains, and the free plan covers 10,000 DMARC messages a month and 2 spam tests, with no card. It is third because it tests and monitors rather than fixes: it does not clean lists or warm up inboxes, extra tests are $16.99 for 3, and Essential is $59 a month billed yearly but $85 monthly.

   GlockApps pricing and details

Ranked on Oct 18, 2026 from what each listing shows and what people say about the tool, not from our own testing. How we rank