Setup Guide

How to Set Up SPF, DKIM, and DMARC for Constant Contact

Constant Contact is an email marketing platform popular with small businesses, nonprofits, and local organizations. If you're sending newsletters, event invitations, or promotional emails through Constant Contact using your own domain, authentication ensures those messages reach your subscribers' inboxes.

SPF Configuration

Constant Contact uses the spf.constantcontact.com include.

DNS Record:

Type:  TXT
Host:  @
Value: v=spf1 include:spf.constantcontact.com ~all

Combined with other services:

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

Verify your total lookup count with the SenderClarity SPF Checker.

DKIM Configuration

Constant Contact supports custom DKIM signing through their Self-Authentication feature.

  1. In Constant Contact, go to My Account → Account Settings → Self-Authentication (or Settings → Domain Authentication).
  2. Enter your domain name.
  3. Constant Contact will provide CNAME or TXT records for DKIM:
Type:  CNAME
Host:  ctct1._domainkey
Value: (provided by Constant Contact)

Type:  CNAME
Host:  ctct2._domainkey
Value: (provided by Constant Contact)
  1. Add the records to your DNS.
  2. Return to Constant Contact and verify.

DMARC Configuration

Start with monitoring mode:

Type:  TXT
Host:  _dmarc
Value: v=DMARC1; p=none; rua=mailto:your-address@reports.senderclarity.com; fo=1

Progress to enforcement:

  1. p=quarantine; pct=25
  2. p=quarantine; pct=100
  3. p=reject

DMARC Considerations for Constant Contact

  • DKIM is your only path to DMARC alignment: Constant Contact uses its own return-path domain for bounce handling, so SPF will never align with your From domain. Self-authentication (custom DKIM) isn't optional — it's the only way Constant Contact emails can pass DMARC.

  • "Via constantcontact.com" signals missing authentication: If Gmail recipients see this label, DKIM isn't set up for your domain. Beyond the cosmetic issue, this means your emails are failing DMARC alignment and will be quarantined or rejected once you enforce your policy.

  • Plan limitations may block you: Self-authentication isn't available on all Constant Contact plans. If your plan doesn't support it, you cannot achieve DMARC compliance through Constant Contact — a serious problem if you're moving toward enforcement. Confirm availability before committing to a DMARC rollout timeline.

Verification

  • Check your SPF record →
  • Send a test email from Constant Contact to yourself
  • Check headers for dkim=pass aligned with your domain
  • Monitor DMARC reports in SenderClarity

Common Issues

"On behalf of" or "via" labels in Gmail: Without custom DKIM, emails from Constant Contact may show "via constantcontact.com" in the sender line. Completing DKIM setup removes this label and improves trust with recipients.

Self-authentication not available: Some older Constant Contact plans may not offer self-authentication. Check with Constant Contact support about upgrading to a plan that supports custom DKIM.

SPF alignment: Constant Contact uses its own return-path domain by default. DKIM alignment is the primary path to DMARC compliance for Constant Contact emails.

SPF Lookup Impact

Include Estimated Lookups
spf.constantcontact.com 1–2