Your Mailchimp emails go to spam mostly because your sending domain is not authenticated. Gmail, Yahoo and Outlook check that an email really comes from the domain in the From line. Without your own DKIM and DMARC records, that check fails, and your newsletter lands in Promotions at best, spam at worst.
The fix takes about 15 minutes: in Mailchimp, open Account & billing, then Domains, click Start authentication, and add 2 CNAME records and 1 TXT record at your domain provider.
TLDR: Authenticate your sending domain in Mailchimp (2 DKIM CNAME records + 1 DMARC TXT record), send from an address on that domain, never from Gmail, and clean out contacts who never open. That fixes most Mailchimp spam problems.
Why Gmail and Yahoo send your Mailchimp email to spam
Since February 2024, Gmail and Yahoo require senders to prove who they are. Outlook followed in 2025 for bulk senders. The proof is three DNS records on your domain:
- SPF lists which servers may send mail for your domain.
- DKIM adds a signature to each email that proves your domain approved it.
- DMARC tells inboxes what to do when the first two fail, and checks that they match the domain in your From line.
When you send from hello@yourbrand.com without authenticating in Mailchimp, Mailchimp signs the email with its own domain, not yours. The From line says yourbrand.com, the signature says Mailchimp. DMARC sees the mismatch and fails. Gmail reads that as "maybe not really them" and files it accordingly.
That is the single most common cause. We saw it ourselves: a newsletter sent through Mailchimp from an unauthenticated domain went straight to a Gmail spam folder, while the same email from an authenticated domain landed in the inbox.
How to authenticate your domain in Mailchimp (step by step)
You need access to your domain's DNS settings (GoDaddy, Cloudflare, Namecheap, Squarespace or your web host). Then:
- Open Domains. Click your profile icon, choose Account & billing (or Account if you are a manager on someone else's account), then the Domains tab.
- Verify the domain. If it is not listed, add it, enter an email address on that domain, and click the verification link Mailchimp sends.
- Click Start authentication next to the verified domain and pick your DNS provider.
- Let Mailchimp do it, or do it by hand. With the recommended option (Entri), you log in to your DNS provider and Mailchimp creates the records. By hand, you copy them yourself.
- Add the records (manual route):
| Record | Type | Host / Name | What it does |
|---|---|---|---|
| DKIM 1 | CNAME | Shown in Mailchimp (CNAME 1) | Signs your email with your domain |
| DKIM 2 | CNAME | Shown in Mailchimp (CNAME 2) | Backup signing key |
| DMARC | TXT | _dmarc |
Tells inboxes how to treat failures |
- Wait and check. Most records work within minutes. Mailchimp says it can take up to 48 hours and emails you when it is done. The domain then shows Authenticated in green.
Copy the exact values from your Mailchimp screen. They are unique to your account.
Do you need SPF for Mailchimp?
No. Mailchimp states that adding its SPF include to your record is not required and does not give DMARC alignment. Mailchimp sends with its own bounce address, so SPF checks Mailchimp's domain, not yours. DKIM is what aligns with your From line.
Keep the SPF record you already have for your normal mailbox. Do not stack extra includes: SPF breaks above 10 DNS lookups.
Your DMARC record: start gentle
If your domain has no DMARC record yet, start with monitoring only:
v=DMARC1; p=none; rua=mailto:dmarc@yourbrand.com
p=nonemeans "watch, do not block". Nothing breaks while you check that every tool sending mail for you is authenticated.- After a few weeks of clean reports, move to
p=quarantine, thenp=rejectif you want full protection against spoofing.
If you already have a DMARC record, do not add a second one. One _dmarc TXT record per domain, or both get ignored.
Never send from a Gmail or Yahoo address
Mailchimp can only authenticate a domain you own. Sending a newsletter "from" yourbrand@gmail.com means the email claims to come from Gmail while Mailchimp's servers send it. Inboxes treat that as suspicious.
Use an address on your own domain, like news@yourbrand.com.
Still landing in spam after authenticating? Check these 5 things
Authentication gets you to the door. These decide if you get in:
- List quality. Bought lists and contacts who signed up years ago and never open are the fastest way to spam. Archive anyone with no opens in 6 to 12 months.
- Complaint rate. Gmail wants spam complaints under 0.3%, ideally under 0.1%. Make your unsubscribe link easy to find; a hidden one turns into a "Report spam" click.
- Image-only emails. One big image with no text looks like a flyer. Keep real text in the body.
- Link shorteners. bit.ly and similar links share reputation with spammers. Use full links.
- A sudden volume jump. Going from 200 to 20,000 recipients overnight looks like a hacked account. Grow sends gradually.
To test, send a campaign to a fresh Gmail and Outlook address of your own and look at where it lands. In Gmail, "Show original" shows DKIM: PASS and DMARC: PASS when the fix worked.
Catch it before you hit send: Mydrop's sender warning
The annoying part of this problem is that you only find out after the email is gone. Mydrop checks it first.
When you write a newsletter in Mydrop and send it through your Mailchimp integration, Mydrop asks Mailchimp whether your sender's domain is authenticated. If it is not, a warning shows in the editor before you schedule, and again in the checks that run before each send. You fix the DNS once, the warning goes away, and every newsletter after that goes out signed with your domain.
The email stays on the same calendar as your social posts, with client approval before it sends if you work for clients. If your newsletter is a recap of the week's posts, this guide to turning social posts into a weekly newsletter shows the template.
Your next step
Open Mailchimp, go to Account & billing, then Domains, and look at your sending domain. If it does not say Authenticated, add the 2 CNAME records and the DMARC record today. Then send your next campaign to your own Gmail and check for DMARC: PASS.
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