Deliverability

Delivery is a reputation game played over months. Here’s how to win it — most of it automated, all of it visible.

Authenticate everything

SPF, DKIM, and DMARC prove you are who you claim to be. Set them up under Domains before sending anything real. Unauthenticated mail is the single fastest route to spam folders.

Warm up gradually

New domains start with limits that lift as your reputation builds. This isn’t punishment — inbox providers distrust sudden volume from unknown senders, and ramping protects the reputation you’re building.

Keep bounces and complaints near zero

Sustained bounce rates above ~2% or complaint rates above ~0.1% will hurt you everywhere, not just with us. Our suppression list enforces this automatically — but the real fix is verifying addresses at signup and making unsubscribe obvious.

Send what people asked for

Transactional email has a natural advantage: the recipient triggered it. Keep it that way. Calder is not a bulk-marketing platform, and that focus is part of why transactional senders here land in inboxes.

Watch the dashboard, not your gut

Per-domain bounce and complaint rates, verification state, and event timelines turn “delivery feels off” into a diagnosable, fixable, specific thing.