One bad tenant can sink your whole email platform: what I learned building a reputation circuit breaker
I'm a solo founder in the UK building SentriSend, a security gateway that sits in front of transactional email (AWS SES / Resend). This week I shipped two features. Building them changed how I think about multi-tenant email, so here's what I learned. Bots push a victim's address into hundreds of signup forms at once. The victim's inbox floods, and every site involved picks up complaints and spam-trap hits. The nasty part is that each individual site only sees one or two "signups". From where an…