InboxProof

InboxProof is a web app + API that continuously monitors email deliverability for product and transactional email. You connect your sending provider (SendGrid, SES, Mailgun, Postmark) and InboxProof seeds real inboxes across major mailbox providers (Gmail, Outlook, Yahoo, iCloud) plus spam traps. It runs scheduled “canary” sends, measures inbox vs spam placement, authentication alignment (SPF/DKIM/DMARC), bounce/complaint signals, and content-based spam triggers. When placement drops or auth breaks (e.g., a DKIM key rotation gone wrong), it alerts Slack/PagerDuty with a clear root-cause checklist and suggested fixes. It also exposes an API so engineering teams can gate releases: block deployments if deliverability health falls below a threshold. This is not a newsletter analytics tool; it’s an operational reliability layer for email.