My email isn't bouncing — it just goes to spam. Is that a different problem?

Yes, and it's a harder one. A bounce is a rejection: the receiving server refuses the message and sends back an error code you can read. Spam-foldering is acceptance followed by a filing decision — the server took your mail, decided it looked untrustworthy, and dropped it in Junk without telling you. There's no error code, no bounce message, nothing in your logs to react to. From the sending side a spam-foldered message and an inboxed one look identical. That silence is exactly why it's worse: you think the email sent, the recipient never sees it, and neither of you finds out until someone asks 'did you get my message?' Because there's no feedback, you have to diagnose the causes directly rather than waiting for the system to tell you what's wrong.

Will changing the words in my email keep it out of spam?

Mostly no, and this is the biggest myth in the whole topic. The folklore — avoid the word 'free,' don't use exclamation marks, limit your links — is decades out of date. Modern filters weigh authentication, sending-domain and IP reputation, and how recipients have engaged with your past mail far more heavily than the vocabulary in any single message. A perfectly worded email from an unauthenticated domain on a bad IP goes to spam; a plain one from a well-authenticated domain with good reputation reaches the inbox. Spend your effort on SPF, DKIM, DMARC alignment, and reputation. Content tweaks are the last 5%, not the first move.

Do I really need DKIM if SPF already passes?

For inbox placement to the big providers, effectively yes. Since February 2024, Gmail and Yahoo require bulk senders (5,000+ messages a day to their users) to authenticate with SPF and DKIM, publish a DMARC record, and use a From: domain that aligns with at least one of SPF or DKIM. Below that volume the rules are guidance rather than a hard gate, but the same filters apply proportionally. DKIM also survives forwarding, where SPF usually breaks — so a message with only SPF often loses its one passing check the moment it's forwarded, while DKIM keeps signing. Set up both.

Emails Going to Spam: Fix Deliverability

What You’re Actually Fixing

Your mail isn’t bouncing. It’s sending, apparently succeeding, and landing in the recipient’s Junk folder — or worse, getting silently filtered before it ever reaches a folder they check. This is a different failure from a bounce, and it needs a different approach, because nothing in your logs is going to tell you it happened. The receiving server accepted your message and then quietly decided it didn’t trust it enough for the inbox.

That decision is made mostly on three things: whether you are who you claim to be (authentication), whether your sending source has a history of behaving (reputation), and whether the people you mail actually want it (engagement). Notice what’s not on that list: the exact words in your email. This guide is for getting the first two right, because that’s where almost every real deliverability problem lives.

Authentication: Passing Isn’t Enough — It Has to Align

Every deliverability checklist tells you to set up SPF, DKIM, and DMARC. Most stop there, and that’s why so many “fully authenticated” domains still land in spam. The part that gets missed is alignment.

SPF says which servers are allowed to send for your domain. It checks the envelope sender (the hidden return-path address), not the From: address your recipient sees.
DKIM attaches a cryptographic signature tied to a signing domain, proving the message wasn’t forged in transit.
DMARC ties the two together and — this is the whole point — checks that the domain SPF or DKIM validated actually matches the domain in the visible From: address.

Here’s the trap. You send through a marketing platform or a transactional service. Their servers pass SPF, but for their bounce domain, not yours. They sign with DKIM, but with their signing domain. Both checks pass — and both fail DMARC alignment, because neither matches your From: address. To a strict filter, a message that passes SPF and DKIM but aligns with neither is unauthenticated, and it gets treated exactly like a spoof. Passing is not the finish line. Aligning is.

Since February 2024, Gmail and Yahoo made this explicit: bulk senders (5,000+ messages a day to their users) must publish a DMARC record and align the From: domain with SPF or DKIM. Under that volume the rule isn’t a hard gate, but the same filters grade you on the same curve.

Reputation: The IP and Domain Carry a History

Filters remember. Your sending IP and your From: domain each carry a running reputation, and a bad one drops you into spam no matter how clean the individual message is.

The most common reputation trap is a brand-new sending source with no history — a fresh VPS, a newly warmed marketing account, a domain that’s never sent before. Providers treat unknown senders with suspicion by default and watch how the first few thousand messages perform. Blast a large cold list on day one and you can poison a new domain’s reputation before it’s had a chance to earn one.

The number that actually matters here is the spam complaint rate. Gmail and Yahoo want it under 0.3%, and Google recommends staying below 0.1% for reliable inbox placement — the 0.3% figure is where enforcement starts, not a safe target. Three complaints per thousand delivered messages is enough to start sinking you. The fix is unglamorous: only mail people who asked to hear from you, make unsubscribing trivial (a working List-Unsubscribe header, required for bulk senders), and remove addresses that bounce or never open.

The One Piece of Infrastructure People Forget

If you run your own mail server, check reverse DNS. The sending IP needs a PTR record whose hostname resolves back to that same IP — forward-confirmed reverse DNS. Many receivers, Gmail included, quietly downgrade or reject mail from an IP with missing or mismatched rDNS, because legitimate mail servers almost always have it and spam sources often don’t. A new server without a PTR is a classic silent spam-folder cause, and it’s set at your IP or cloud provider, not in your normal DNS panel.

Diagnose with DechoNet

Email Check reads your domain’s SPF, DKIM, and DMARC exactly the way a receiving server does — including whether they align with your From: domain, which is the check most tools skip. Run it before you touch anything else; it tells you whether the problem is authentication or something downstream.
Reverse DNS Check confirms your sending IP has a valid PTR record that matches your mail hostname. If Email Check is clean but mail still lands in spam, a missing or wrong rDNS is the next thing to rule out.

Verification Checklist

Confirm SPF exists and lists the servers that actually send your mail — including any third-party platform, added by their include: mechanism, not by pasting IPs.
Confirm DKIM is signing, and that the signing domain matches (aligns with) your From: domain.
Confirm a DMARC record is published (start at p=none so you can read reports before you enforce).
Verify alignment, not just passing: the domain SPF or DKIM validated must match your visible From: address.
Check the sending IP’s PTR record resolves back to your mail hostname.
Send a test to an account at the provider you’re missing (Gmail, Outlook), open the raw headers, and read the Authentication-Results line — it shows spf=, dkim=, and dmarc= verdicts from the receiver’s own point of view.
If you send in volume, set up the provider’s postmaster or sender dashboard and watch your complaint rate against the 0.3% ceiling.

When It’s Not Your Setup

If authentication aligns, the IP has clean rDNS, and your complaint rate is low, but one specific recipient still finds your mail in spam, the decision has moved to their side. Corporate mail systems and individual spam filters make per-recipient calls that no amount of sender hygiene overrides. At that point the reliable fix is on the receiving end: have the recipient add you to their contacts or mark one message “Not Spam,” which teaches their filter far faster than anything you can do from where you’re sending.

Check your own domain now

Free, no sign-up. Runs the exact check this guide describes and shows what to fix.