Setting up SPF, DKIM and DMARC for Constant Contact

Constant Contact's authentication setup splits across three separate steps - SPF is a DNS include, DKIM is a toggle plus a DNS record generated for your account, and DMARC is entirely self-managed.

Step 1: Add Constant Contact to your SPF record

yourdomain.com.    TXT    "v=spf1 include:constantcontact.com ~all"

If you already have an SPF record from another sender, add the include to the existing record - never publish two SPF TXT records on the same domain:

yourdomain.com.    TXT    "v=spf1 include:constantcontact.com include:_spf.google.com ~all"

Verify with:

$ dig yourdomain.com TXT +short

You should see exactly one TXT record starting with v=spf1.

Step 2: Enable DKIM inside Constant Contact

In Constant Contact's account settings, under email authentication, you turn on DKIM signing for your domain. It generates a CNAME for you to publish - the hostname and target are specific to your account, so copy them directly from that screen rather than typing a guessed value. It will look structurally like:

ctctYYYYMM._domainkey.yourdomain.com.    CNAME    <value shown in your account>.

Publish it, then go back into Constant Contact and use its "verify" button, or check manually:

$ dig ctctYYYYMM._domainkey.yourdomain.com CNAME +short

A result means the record is live. DKIM only actually signs mail once Constant Contact's own toggle confirms the record resolves - publishing the DNS record alone is not enough.

Step 3: Publish DMARC yourself

Constant Contact does not create or manage a DMARC record for you. Add it at your domain's root:

_dmarc.yourdomain.com.    TXT    "v=DMARC1; p=none; rua=mailto:dmarc-reports@yourdomain.com"

Start at p=none so you can read aggregate reports before enforcing anything. Give it two to three weeks of reporting, confirm your Constant Contact traffic is passing and aligned, then step up to p=quarantine.

Verifying the whole chain

Send a real campaign to a mailbox you control (Gmail is useful here because it exposes authentication results plainly) and check the message's original headers for:

Authentication-Results: mx.google.com;
       dkim=pass header.d=yourdomain.com;
       spf=pass smtp.mailfrom=...constantcontact.com;
       dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=yourdomain.com

dkim=pass header.d=yourdomain.com is the one that matters most for DMARC - it confirms the DKIM signature's domain matches your visible sending domain, which is what DMARC alignment actually checks.

What not to do

• Don't leave DKIM disabled in Constant Contact's settings after publishing the CNAME - the record existing in DNS does nothing until the sending side turns signing on.
• Don't publish a second v=spf1 TXT record if you already have one from another provider; merge the include instead.
• Don't jump straight to p=reject on DMARC - a misconfigured include or an unaligned legacy sender will get silently dropped with no warning.

Constant Contact authentication quick reference

FAQ

Why does Constant Contact ask me to both publish a DNS record and click "enable" in its dashboard? The DNS record only makes the public key available for receivers to verify against. Constant Contact's own toggle controls whether its sending infrastructure actually signs your outgoing mail with that key - both steps are required, and missing either one leaves DKIM inactive even though it looks configured.

I verified DKIM in Constant Contact months ago - do I need to recheck it? It's worth a periodic spot-check, particularly after any DNS migration (changing registrars or DNS hosts) since CNAME records can be dropped during a transfer if whoever performs the migration doesn't carry over every record.

Does Constant Contact support a custom DKIM selector? The selector format Constant Contact uses is account-generated and not something you choose yourself - always copy the exact value from your account's settings rather than assuming a fixed pattern.

MailPilot checks SPF, DKIM, and DMARC status for the mailboxes it warms and reports per-provider inbox placement, so once your Constant Contact authentication is live

What if I manage several domains through one Constant Contact account? Each domain needs its own separate domain authentication setup - DKIM and SPF records are per-domain, so completing the process for one sending domain does not extend coverage to a second one, even under the same account.

Does Constant Contact support BIMI or only SPF/DKIM/DMARC? Constant Contact's authentication settings focus on SPF and DKIM for deliverability, plus leaving DMARC to you - BIMI, which controls whether your logo appears next to authenticated mail, is a separate, additional record built on top of an enforced DMARC policy and isn't part of the base setup described here. you can see whether it's actually translating into inbox delivery at Gmail, Outlook, and Yahoo.