Guides / Why are my cold emails going to spam?
Why are my cold emails going to spam?
Almost nobody has one single reason. Cold emails land in spam because of a stack of small things: broken authentication, a young domain, too much volume too fast, a bad list, or a listing on a blocklist. The trick is to check them in the right order, because the cheap, mechanical causes are the ones you can fix in an afternoon. Rewriting your copy is usually the last thing to try, not the first.
Step 1: confirm the email actually went to spam
Before you fix anything, make sure there is a problem. Open rates are an unreliable signal, because many tools count image loads and privacy features inflate or deflate them. Instead, send a plain test message from the same mailbox to a Gmail, an Outlook and a Yahoo address you control, and look at where each one lands.
If the test lands in the inbox but your campaign does not get replies, you may have a targeting or message problem rather than a deliverability one. If the test lands in spam, keep reading.
Step 2: read the authentication results
In Gmail, open the message that landed in spam, choose the three-dot menu and then Show original. Near the top you will see lines for SPF, DKIM and DMARC. You want to see PASS on all three, and you want them to pass for the same domain that appears in your visible From address. This is called alignment.
A very common cold email failure is that SPF passes for the sending tool's domain but not yours, and DKIM is signed by the tool rather than by you. DMARC then fails because neither result aligns with your From domain. The fix is usually to set up custom DKIM signing for your own domain inside your sending tool and publish the DNS record it gives you.
- SPF fail or softfail: the sending server is not listed in your SPF record.
- DKIM none or fail: no signature, or the public key in DNS does not match.
- DMARC fail: neither SPF nor DKIM passed with alignment to your From domain.
Step 3: check for DNS mistakes
Authentication problems often come from DNS, not from the email itself. Look for more than one SPF record on the same domain (only one is allowed), an SPF record that needs more than 10 DNS lookups, a missing DMARC record, or a DKIM record published under the wrong selector name. Our guides on SPF lookups and DKIM selectors in Google Workspace cover the two most frequent ones.
Our free checker looks at all of these in one go, so you do not need to run four separate lookups by hand.
Step 4: look at the age and history of the domain
Mailbox providers keep a reputation for your sending domain. A brand-new domain has none, and a domain that suddenly starts sending hundreds of messages a day looks like exactly what spammers do. Ramp volume gradually, starting small, and keep it steady. We explain a sensible approach in the domain warm-up guide.
Also consider whether you are sending cold email from your main company domain. If that domain gets damaged, ordinary company email can suffer too. Many senders use a separate domain for outreach, covered in using a secondary domain for cold email.
Step 5: check blocklists
Check whether your sending domain or the IP address you send from appears on a major blocklist. A listing does not always mean you will be blocked, since not every receiver uses every list, but it is worth knowing. See how to check whether your domain is blacklisted for what the common lists mean and what to do about a listing.
Step 6: check complaints, bounces and the list itself
Google and Yahoo both say senders should keep their spam complaint rate under 0.3%, and Google recommends staying well below that. Cold email is unsolicited, so complaints are a real risk. A high bounce rate also hurts, and it usually comes from an old or purchased list with addresses that no longer exist. Verify addresses before sending and remove anyone who bounces or asks to stop. See the complaint rate guide.
Step 7: only now look at content
Content matters less than most people think, but it is not irrelevant. Things that tend to hurt: lots of links, tracking links on a shared or mismatched domain, large images, attachments, heavy HTML, all-caps subject lines and misleading claims. Plain, short, relevant text sent to the right person is the safest format. Send to people who plausibly want to hear from you, and make it easy to opt out.
Work through the list in order
If you take one thing from this page, it is the order: confirm the problem, read the authentication results, fix DNS, review domain age and volume, check blocklists, review complaints and list quality, and only then edit copy. Most cold email spam problems are found in the first three steps. For a single printable list, use the cold email deliverability checklist.
Frequently asked questions
Why do my cold emails go to spam even though SPF, DKIM and DMARC pass?
Passing authentication is necessary but not enough. Reputation, sending volume, list quality, complaints and content all still affect placement. Authentication only proves who you are, not that people want your email.
Is it my copy or my domain?
Check the domain and authentication first. They are easier to verify and fix. If a plain test message lands in spam, the problem is almost certainly not your copy.
Can a blacklist cause emails to go to spam?
Yes, if the receiving server uses that list. Many listings affect only some receivers, so a listing is a reason to investigate rather than proof of the cause.
How long does it take to fix deliverability?
DNS fixes can take effect within hours to a day or so. Reputation recovery is slower and depends on how your sending behavior changes. We can't give a guaranteed timeline.