Email Deliverability That's Handled For You
Domain authentication happens automatically when you send through CircleHQ, backed by 99.9% uptime, full delivery logs, and tools that keep your list clean.
Authentication, uptime, list hygiene, and better engagement — the four levers that actually move deliverability.
Authentication that happens without touching your DNS
Deliverability problems usually trace back to authentication, not content. If a sending domain is not properly set up with SPF, DKIM, and DMARC records, inbox providers treat the mail as suspicious before a single subscriber sees it. CircleHQ handles this automatically for every account, so there is no DNS configuration checklist to work through before your first campaign sends. That matters most for programmatic and transactional sending, OTPs, password resets, order confirmations, where a delivery delay or spam-folder landing turns into a support ticket instead of a marketing metric.
See what happened to every message, not just whether it sent
Sending an email is not the same as it arriving. CircleHQ's transactional messaging runs on 99.9% estimated uptime with full delivery logs, so you can see exactly when a message sent, delivered, bounced, or opened instead of guessing why a customer says they never got it. That visibility applies across email, SMS, and push from one API, which matters if you are running your own sending infrastructure today and weighing what an on-premise mail transfer agent gives you against a platform that logs every step by default.
A clean list is still the biggest lever you control
Authentication and uptime solve the technical half of deliverability. The other half is list quality: sending to addresses that bounce, never engage, or mark you as spam is what actually damages sender reputation over time, regardless of how well the domain is configured. Circle AI can build a segment for contacts who have not opened an email in 90 days, so you can pause or re-engage them before they drag down your reputation with every other subscriber, and forms with built-in validation keep obviously fake addresses off the list before they arrive.
Better subject lines are a deliverability lever too
Engagement signals, opens, clicks, replies, feed directly into how inbox providers score a sender's reputation. Circle AI drafts subject line variants and tests them automatically to find what actually gets opened, so improving deliverability is not just a technical checklist but an ongoing part of how campaigns get written. A subject line half the list ignores is a deliverability problem wearing a copywriting disguise.
The tools that keep your emails landing in the inbox, not the spam folder.
Automatic authentication
SPF, DKIM, and DMARC are configured for every account automatically, so campaigns send with proper authentication from day one.
Full delivery logs
Every message has a delivery log showing sent, delivered, bounced, and opened status across email, SMS, and push from one API.
List hygiene tools
Circle AI builds segments of unengaged contacts so you can pause or re-engage them before they pull down sender reputation.
AI subject line testing
Circle AI drafts and tests subject line variants automatically, so engagement stays high and inbox providers keep scoring you well.