Deliverability best practices
Getting accepted by the API is easy; landing in the inbox is the real goal. Mailhuset handles the infrastructure, but inbox placement also depends on how you send. The essentials:
Watch your reputation
The Deliverability page pulls your sending health into one view: delivery, bounce and complaint rates checked against safe limits, each domain's SPF/DKIM, return-path and DMARC status, DMARC alignment (who is sending as you), and your suppression breakdown — plus specific recommendations when something needs attention. Check it regularly, and especially before a large send.
Authenticate everything
Verify your domain so SPF and DKIM pass, and publish a DMARC record. This is non-negotiable for modern inboxes (Gmail and Yahoo require it for bulk senders). See Verify a sending domain.
Use a subdomain for sending
Send from mail.yourdomain.com rather than your root domain. It isolates your sending reputation and keeps a reputation problem from affecting your corporate email.
Separate transactional and bulk
Send receipts/resets on the transactional stream and newsletters on the broadcast stream. Mixing them lets bulk-mail reputation drag down your critical transactional mail. Set "stream": "broadcast" when sending bulk.
Warm up gradually
A brand-new domain has no reputation. Ramp volume over days/weeks rather than blasting from zero. Mailbox providers distrust sudden spikes.
Keep your list clean
- Only send to people who asked for it. Purchased lists wreck reputation.
- Honor unsubscribes immediately (Mailhuset's suppressions
enforce this automatically).
- Remove chronically non-engaging addresses.
Watch bounces and complaints
- Hard bounces (bad address) and complaints (spam reports) are
auto-suppressed. A rising complaint rate is a red flag. Investigate content and consent.
- Monitor these in Activity and via webhooks.
Content matters
Use a real, monitored from and reply-to, a clear subject, a plaintext part alongside HTML, and avoid spammy patterns (all-caps, link shorteners, huge images with little text).
Not sure? Use the spam-score check when composing a broadcast or template (or the POST /v1/content/check API): it scores your subject and body and flags the common, fixable problems — a shouting subject, HTML with no plain-text part, an image-heavy body, too many links, URL shorteners, or a missing unsubscribe link — before you send. It's guidance, not a guarantee; authentication still matters most.
Add one-click unsubscribe for bulk
For broadcasts, include list-unsubscribe headers so recipients can opt out in one click, required by Gmail/Yahoo for bulk senders and far better than being marked as spam.
Need help? Email support@mailhuset.com.