Domain Health

8 min read Last updated: June 23, 2026

Domain Monitoring

Domain Health is ProperSend's monitoring center for email authentication and domain reputation. It checks your DNS configuration, blacklist status, and spam score — all in one dashboard. Without proper DNS configuration, even the best campaign content lands in spam.

When to use Domain Health: Before launching any campaign (verify DNS is correct), after adding new mailboxes (confirm authentication), and weekly during active campaigns (catch issues early). Also check immediately if you notice a drop in open rate or an increase in bounce rate.

Navigate to app.propersend.pl/health to check your domain status.

DNS Records

ProperSend validates the following DNS records for each of your sending domains.

SPF (Sender Policy Framework)

Defines which mail servers are authorized to send email from your domain. Without SPF, anyone can send emails "from your domain."

v=spf1 include:_spf.google.com ~all

Meaning: include:_spf.google.com allows Google servers to send. ~all (softfail) or -all (fail) tells receiving servers what to do with unauthorized senders.

ProperSend checks:

  • Whether the SPF record exists in DNS
  • Whether it covers all sending servers (if using multiple providers)
  • Whether there are syntax errors or too many DNS lookups (max: 10)

⚠️ Note: SPF has a 10 DNS lookup limit. If you use multiple services (Google, Mailchimp, ProperSend), you may exceed it. Use SPF optimization tools or consider relying more on DKIM.

DKIM (DomainKeys Identified Mail)

Adds a digital signature to each outgoing message. Receiving servers verify this signature to confirm the email hasn't been tampered with and genuinely came from your domain.

You generate a key pair (public/private) in your email provider's panel. The public key is added as a TXT record in DNS; the private key stays with the provider.

DMARC (Domain-based Message Authentication, Reporting & Conformance)

Tells receiving servers what to do with messages that fail SPF and/or DKIM authentication. It acts as the "judge" for email authentication.

v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com

Available DMARC policies: | Policy | Description | When to Use | |--------|-------------|-------------| | p=none | Monitor only — don't block, but collect reports | First 2-4 weeks — gather data | | p=quarantine | Mark failures as spam | Once authentication is confirmed working | | p=reject | Reject failures entirely | Target policy — highest protection |

💡 Tip: Start with p=none for the first few weeks, review DMARC reports, then switch to p=quarantine or p=reject. Switching to p=reject without testing can block legitimate emails. Configure Notifications for domain status changes to react immediately.

MX Records

Define incoming mail servers. ProperSend checks whether MX records exist and are correctly configured. Without MX records, you can't receive replies to your emails.

PTR (Reverse DNS)

Binds a server IP to a domain name. Required by many providers (Gmail, Outlook) to accept messages. If you use a dedicated sending IP, PTR is mandatory — configure it through your hosting provider.

TLS

Checks whether the receiving server supports encrypted connections. Today, lack of TLS means automatic rejection by Gmail and Outlook.

Example Complete DNS Configuration

SPF:    v=spf1 include:_spf.google.com ~all
DKIM:   google._domainkey TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC..."
DMARC:  _dmarc TXT "v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com"
MX:     @ MX 10 aspmx.l.google.com
PTR:    123.456.789.0 → mail.yourdomain.com (configure at hosting provider)

Blacklist Monitoring

ProperSend automatically checks your sending IPs and domains against major email blacklists:

  • Spamhaus – the most widely used DNSBL
  • Barracuda – used by many corporate email systems
  • SURBL – checks URLs within email bodies
  • SpamCop – based on user spam reports
  • Invaluement – real-time threat detection

If your domain appears on any blacklist, Domain Health flags it immediately so you can investigate and request delisting. Status: ✅ Clean means you're not on any blacklist.

⚠️ Note: If you land on a blacklist (status other than Clean), campaigns using this domain are automatically paused. To be removed, follow the delisting instructions on the respective provider's site — typically this requires fixing DNS configuration and submitting a delisting request.

Spam Score

The spam score predicts how likely your emails are to be flagged as spam, based on content and authentication signals:

| Score | Meaning | |-------|---------| | 0-2 | Low spam risk — good deliverability expected | | 3-5 | Medium risk — review content and authentication | | 6+ | High risk — campaign may be blocked or filtered to spam |

Tip: If your spam score is 3+, check your DNS records (SPF, DKIM, DMARC), review email content for spam trigger words, and verify your Suppressions list is up to date. Also run Email Verification to remove invalid addresses from your lists.

Health Guard (3 Strikes Rule)

Health Guard protects your domain reputation by automatically reacting to deliverability issues:

  1. Strike 1 – Alert triggered. The affected campaign is auto-paused. You receive a notification (see Notifications).
  2. Strike 2 – Warning issued. All campaigns using this domain are paused to prevent further reputation damage.
  3. Strike 3 – Domain enters a 24-hour cooldown period. No emails can be sent from this domain until the cooldown expires.

After resolving the root cause (e.g., fixing DNS records or delisting from blacklists), you can manually reset the strikes from the Health dashboard.

Health Guard reacts to:

  • Sudden spike in bounce rate (above 10%)
  • Spam complaint
  • Blacklist detection (appearing on any major blacklist)
  • Authentication failure (SPF/DKIM/DMARC stopped working)

Trend Monitoring

The system shows the domain health trend over time, helping you spot issues before they become critical:

| Trend | Meaning | Action | |-------|---------|--------| | Stable | Everything is fine | Routine monitoring | | Improving | Reputation is recovering | Continue good practices | | Declining | Something is wrong — investigate | Check campaign stats, bounce rate, blacklists | | Critical | Requires immediate attention | Pause campaigns, check DNS and blacklists |

Best Practices

  1. Check Domain Health before every campaign — confirm SPF, DKIM, DMARC are correct
  2. Monitor the trend regularly — if you see "Declining", act immediately, don't wait for "Critical"
  3. Don't ignore blacklists — landing on Spamhaus is a serious issue. Act immediately
  4. Keep DMARC on p=quarantine or p=reject — p=none is only a transitional phase
  5. Configure PTR — if you have a dedicated sending IP, PTR is essential

Best Practice: Review Domain Health weekly during active campaigns. Catching an SPF misconfiguration or a blacklist listing early can save weeks of reputation recovery.