Owlat Docs

Deliverability

Deliverability is about making sure your emails actually reach your recipients' inboxes — not their spam folder, and not a bounce. Good deliverability...

Deliverability is about making sure your emails actually reach your recipients' inboxes — not their spam folder, and not a bounce. Good deliverability requires verified sending domains, clean audience lists, and proper compliance practices.

Domain setup

Before you can send emails, you need to verify at least one sending domain. This proves to email providers (Gmail, Outlook, etc.) that you're authorized to send from that domain.

Adding a domain

  1. Open Settings > Domains.
  2. Click Add Domain and enter your domain name.
  3. Owlat generates the DNS records you need to add.

Required DNS records

You'll need to add several DNS records to your domain provider (Cloudflare, Route 53, GoDaddy, etc.):

RecordPurpose
SPFTells email providers which servers are allowed to send email from your domain. Without this, your emails may be rejected.
DKIM (3 records)Adds a cryptographic signature to your emails so recipients can verify they haven't been tampered with.
DMARCDefines what should happen when an email fails SPF or DKIM checks — reject it, quarantine it, or let it through. A DMARC policy protects your domain from spoofing.
MAIL FROM (MX + SPF)Sets up a custom return-path domain for full SPF alignment. This improves deliverability by ensuring both the sender address and the return-path match your domain.

Add all records, including the MAIL FROM records. While some are technically optional, each one improves your deliverability score. The MAIL FROM domain in particular helps with DMARC alignment, which many email providers now require.

Verification flow

  1. Registering — your domain is being set up. DNS records are generated.
  2. Pending — records are displayed. Add them to your DNS provider.
  3. Click Verify — Owlat checks that your DNS records are in place and correctly configured.
  4. Verified — all checks passed. You're ready to send.

DNS changes can take anywhere from a few minutes to 48 hours to propagate, depending on your DNS provider. If verification fails, wait a bit and try again.

Blocklist management

Owlat automatically blocks sends to email addresses that have caused problems — hard bounces, spam complaints, and other delivery failures. This protects your sender reputation.

How contacts get blocklisted

Contacts are automatically added to the blocklist when:

  • An email bounces (hard bounce from the email provider)
  • A recipient files a spam complaint

You can also manually add addresses to the blocklist from Settings > Blocklist.

How the blocklist affects sending

Blocked contacts are skipped during campaign sends — they won't receive any marketing emails. This happens automatically; you don't need to exclude them manually when selecting your audience.

Viewing the blocklist

Open Settings > Blocklist to see blocked addresses. For each entry you'll find:

  • Email address — the blocked recipient
  • Reason — why they were blocked (bounce, complaint, manual)
  • Date — when they were added

Managing blocked addresses

In most cases, you should leave blocklist entries in place — they're there for a reason. However, if you know an address is valid and the block was a one-time issue (like a temporary mailbox-full bounce), you can remove the entry to allow re-sending.

Be cautious about removing blocklist entries. Repeatedly sending to addresses that bounce or generate complaints will damage your sender reputation with email providers, which affects delivery for all your emails.

Unsubscribe and preferences

Owlat includes built-in unsubscribe and preference management to keep you compliant:

  • One-click unsubscribe — every marketing email includes an unsubscribe mechanism that meets CAN-SPAM and GDPR requirements
  • Preference center — contacts can manage their per-list subscription preferences, choosing which mailing lists they want to remain subscribed to

Preference center

The preference center is a hosted page where contacts can manage their own subscriptions. It shows all mailing lists the contact belongs to and lets them opt out of individual lists without unsubscribing from everything.

  • Links to the preference center are automatically included in email footers
  • Access is secured with HMAC-signed tokens — contacts can only view and modify their own preferences
  • Available at the /preferences public endpoint

These work automatically for all marketing campaigns. You don't need to set anything up.

Compliance essentials

Email laws vary by region, but the core principles are universal:

CAN-SPAM (United States)

  • Include a valid physical mailing address
  • Provide a clear unsubscribe mechanism (handled automatically by Owlat)
  • Honor unsubscribe requests promptly
  • Don't use misleading subject lines or sender information

GDPR (European Union)

  • Obtain explicit consent before sending marketing emails
  • Provide easy opt-out mechanisms
  • Respect data subject access and deletion requests
  • Document your consent collection process

General best practices

  • Only send to people who have opted in
  • Make it easy to unsubscribe
  • Set clear expectations about what subscribers will receive
  • Process unsubscribes and complaints quickly

Sending hygiene checklist

Good deliverability is an ongoing practice, not a one-time setup:

  • Verify your domain before your first send
  • Start small — warm up a new domain by sending smaller batches first and gradually increasing volume
  • Keep bounce rates low — remove invalid addresses after they bounce
  • Keep complaint rates below 0.1% — high complaints signal to email providers that your emails aren't wanted
  • Clean your lists regularly — remove contacts who haven't engaged in 6+ months
  • Use double opt-in on public signup forms to verify email ownership
  • Monitor your metrics — watch for sudden changes in open rates, bounce rates, or complaint rates

Next steps

Next API Keys & Webhooks