AI · alternatives · 2026
24 alternatives to InboxOK
Email watchdog fixing delivery issues before the spam folder
Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes.
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Preview, analyze & test emails with one click
2022 · inboxpirates.com · its alternatives →
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InboxSDK▲508First usable API to write Gmail Apps for 1B active users
2015 · inboxsdk.com · its alternatives →
- 3OS
Hi HN! We’re Aleem, Chris, Borys, Meichen and Zach from Streak (YC S11) and today we’re open sourcing our InboxSDK https://www.inboxsdk.com, which makes it easy to build apps for Gmail. Over 1.8B users spend their days in Gmail! Having your app built into the Gmail workflow is a better user experience and gives you great user retention. InboxSDK gives you a high-level, declarative API to insert your UI into Gmail without having to directly manipulate the DOM yourself. End users install a browser extension to use your app. The SDK can add UI to multiple areas of Gmail. For example,…
2022 · its alternatives →
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Mailook▲309Identify & fix your email deliverability issues for free
2021 · mailook.ai · its alternatives →
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Free email deliverability checker for SPF, DKIM & DMARC
May 2026 · inboxgreen.email · its alternatives →
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Supamail AI▲214I run multiple projects and D2C brands, which means I manage 6 different Gmail accounts and easily get 100+ emails a day - team updates, invoices, customer queries, newsletters, OTPs… everything mixed together. After missing a few important emails that actually cost me money, I realized the problem wasn’t the number of emails, it was how hard it was to make sense of them. So I built Supamail, an AI-powered inbox that helps you read less and understand more. Here’s what it does: - Emails in last 24 hrs shrink into clear summaries, smart categories, and easy replies so you never feel…
2025 · supamail.co · its alternatives →
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Infraova▲7Monitor and secure your email domains, campaigns, and client
Jul 2026 · infraova.com · its alternatives →
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Get alerted the moment your DMARC, SPF, or DKIM breaks
Jul 2026 · emailposture.com · its alternatives →
- 12
Hi HN :) really excited to share this with you. The one thing AI reliably does is generate noise. Half the tools I see launch are just machines for producing more noise across more channels. And people are starting to see this in the form of emails in their inboxes as spam filters are struggling. There used to be a useful signal in email: the effort a sender put into customizing a message was a rough proxy for how relevant it actually was. AI killed that. Now it's customized slop with the appearance of effort with none of the cost. It is painful that the open internet / open channels…
Jul 2026 · captchainbox.com · its alternatives →
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DMARC Digests▲101Protect your brand from email scammers.
2020 · dmarcdigests.com · its alternatives →
- 14
I've spent the last few months working on something I wish I'd had years ago. I kept running into the same issue: CI green, production mail broken. TLS handshake failures, DKIM alignment mismatches, SPF soft-fails ... the stuff that only surfaces when real mail servers are involved. Most test tools (Mailpit, MailHog) are catch-alls. They confirm "an email was sent" but don't validate the protocol. They also aren't designed for network-exposed environments: no auth, unprotected Web UI, easy to enumerate messages. VaultSandbox is my attempt at fixing that. It's a self-hosted SMTP gateway…
Jan 2026 · vaultsandbox.com · its alternatives →
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Email deliverability audit + AI writer. Free. 60 seconds.
Mar 2026 · checkemaildelivery.com · its alternatives →
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Instantly audit SPF, DKIM & DMARC to stop landing in spam.
Aug 2026 · web-production-80c77.up.railway.app · its alternatives →
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Catch cold email launch blockers before you send
Jun 2026 · outboundqa.com · its alternatives →
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DMARC Monitoring For Everyone Who Isn't A Security Team
Jul 2026 · trustyourinbox.com · its alternatives →
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Check why your emails go to spam — instantly.
Nov 2025 · mailtested.com · its alternatives →
- 24MF
I always assumed Gmail bloat came from large attachments. Turns out 3 senders were responsible for 30% of my inbox — thousands of tiny emails I'd never thought to clean up. I built mailtrim to surface this pattern: - ranks senders by actual storage impact (not just count) - confidence scoring on what's safe to bulk-delete - 30-day undo on everything — nothing is permanent by default - runs entirely locally, no email data leaves your machine Free, open source (MIT). No subscription, no backend. One friction point upfront: Gmail API setup is one-time, ~15 min. After that it's just `mailtrim…
Apr 2026 · its alternatives →
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Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →