Mailchimp / Mandrill: DKIM Selector & SPF Setup

Mailchimp / Mandrill DKIM setup

Mailchimp → Website → Domains → Start Authentication. Publish the CNAME k1._domainkey → dkim.mcsv.net (Mandrill transactional adds mandrill._domainkey TXT). Older setups may also use k2/k3.

Mailchimp campaigns and Mandrill transactional authenticate differently — check both selectors if you use both products.

Mailchimp / Mandrill SPF record

Your SPF TXT record on the root domain must contain include:servers.mcsv.net. A minimal correct record: v=spf1 include:servers.mcsv.net ~all. Stacking multiple ESPs? Each include costs DNS lookups against the limit of 10 — count yours here.

Verify all three pillars

DKIM alone doesn't inbox. Run the full domain grade to confirm SPF, DMARC, MX and blacklist status in one shot — Gmail and Microsoft require alignment across all of them for cold outreach in 2026.