InboxStack
GlockApps
Email Testing By Inbox Pirates
Validity LLC
MxToolBox
Folderly
HetrixTools
Inbox AI
MailGenius
GlockApps
MxToolBox
MailMoxie
Email Testing By Inbox Pirates
Email on Acid
Litmus
Folderly
InboxStack is an email deliverability intelligence platform built for teams who need to know why their emails aren't reaching the inbox โ not just that they aren't. At its core is Brain, a proprietary causal AI engine trained on a 22-year deliverability knowledge base, which correlates signals across your ESP, DNS authentication records (SPF, DKIM, DMARC), Google Postmaster Tools, Microsoft SNDS, and 50+ blocklists to pinpoint root causes instead of surfacing raw metrics.
Most deliverability tools stop at monitoring: they show you a drop in inbox placement or a blocklist hit and leave you to investigate. InboxStack goes further, tracing the actual causal chain โ a DKIM misalignment, a reputation dip on a specific sending IP, a content trigger โ so you can fix the real problem instead of guessing.
Setup takes minutes with no migration required: forward your email headers for an instant DNS/authentication audit, or connect your existing ESP and Postmaster accounts for ongoing monitoring. Optional seed testing gives you real inbox-vs-spam placement data across major providers.
Built for agencies managing multiple client domains and growing companies who've outgrown basic authentication checkers, InboxStack turns deliverability from a black box into a diagnosable, fixable system.
MailGenius is an email testing and deliverability platform that helps you predict where your marketing emails are likely to land before you send them, whether that is the inbox, the Promotions tab, or the Spam folder. It includes a free spam score checker that evaluates important deliverability factors such as email content, links, and sender reputation. For many users, improving inbox placement and avoiding Promotions and Spam can result in a 15โ20% increase in revenue.
InboxStack MailGeniusGlockApps - G-Lock Apps is an interesting tool that might seem simple to some, but is quite essential to most online marketers.
Email Testing By Inbox Pirates - Preview, Analyze & Test emails with one click.
MxToolBox - All of your MX record, DNS, blacklist and SMTP diagnostics in one integrated tool.
Validity LLC - Founded in 2010, located in Essex Countyโs City of Orange, NJ, and serving all 50 states of the U.S., Validity, LLC is considered a โOne Stop Shopโ for ...
MailMoxie - All-in-One Email Deliverability & Accessibility Suite.
Folderly - Folderly is an all-in-one email deliverability platform to supercharge your email performance. Locate, solve, prevent email deliverability pitfalls, and ensure that your emails reach the Inbox folder.