SPF, DKIM and DMARC for Campaign Monitor

Short answer: Campaign Monitor mail passes Gmail, Yahoo and Microsoft checks when you turn on DKIM with your own domain, add include:_spf.createsend.com to your one SPF record and publish a DMARC record at _dmarc (start with p=none). The exact records and clicks are below.

SPF	TXT at `@`	v=spf1 include:_spf.createsend.com ~all Optional, but Campaign Monitor recommends it: add `include:_spf.createsend.com` right after `v=spf1` in your one SPF record. DMARC passes through DKIM either way.
DKIM	CNAME / TXT	TXT record at `cm._domainkey` (on the exact domain or subdomain you send from) with the key Campaign Monitor generates. It starts with `k=rsa; p=`.
DMARC	TXT at `_dmarc`	v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com Start with `p=none` and a mailbox you read, or a free report address that turns the reports into a dashboard; build your own.

Step by step

In Campaign Monitor click your profile image → Account settings → Sending domains → Set up a sending domain.
Enter the exact domain you send from, such as mail.example.com, and click Continue.
Add the DKIM TXT record it shows at your DNS host (TTL 300, or your host's minimum), then click I've added the records.
No DMARC record on that domain? Add v=DMARC1; p=none; at _dmarc and click Re-check record.
Add the SPF include and re-check once more.

Mistakes that break it

Authenticating example.com doesn't cover mail.example.com: set up each domain you send from.
Some DNS hosts want the full cm._domainkey.mail.example.com, others only cm._domainkey (or cm._domainkey.mail for a subdomain).
A DNS host that rejects semicolons or underscores can't hold the key; try \; for semicolons, otherwise move DNS to another host.
Already have a DMARC record? Keep it: changing an existing policy can block other mail of yours.

Check that it worked

After the fix, keep an eye on it: free DMARC monitoring shows every service that sends mail as your domain and which ones fail, in plain English.

Rather not touch DNS? I set up SPF, DKIM and DMARC without breaking your other senders, with a before/after report.

Get it fixed on Fiverr

Prefer to do it yourself? Get the step-by-step Fix Kit ($15) – 19-page guide, checklist, 20+ providers.

Other setup guides

Google Workspace · Microsoft 365 · Zoho Mail · Hostinger Email · Titan Email · GoDaddy email (Microsoft 365 and Professional Email) · Namecheap Private Email · IONOS Mail · Proton Mail · Cloudflare Email Routing · Mailchimp · SendGrid · Amazon SES · Shopify Email · Klaviyo · HubSpot · Brevo · Mailgun · Postmark · Zendesk · Constant Contact · MailerLite · Kit (ConvertKit) · ActiveCampaign · Freshdesk · Intercom · Zoho Campaigns · Help Scout · Squarespace Email Campaigns · Mailjet · Salesforce Account Engagement (Pardot)