You know the drill. A customer complains their transactional emails land in spam. Or a B2B trial signup uses a throwaway address. Or someone asks "do we have DMARC set up correctly?" and you open ten browser tabs to find out. I built MailSec to replace that entire workflow with one API call. The problem Email infrastructure is deceptively complex: SPF has a hard 10-lookup limit that silently breaks when you add one too many include: DMARC with p=none does literally nothing — but most teams ship it and assume they're protected DKIM selectors vary by provider ( google , selector1 , k1 , s1 ) and you need to guess which one to check Spamhaus listings can tank your deliverability for days before anyone notices DNSSEC is either there or it isn't, and most tools make you check separately The information is all in DNS, but it's scattered across different record types, different query tools, and different mental models.…