How to improve email deliverability

If your emails are landing in spam (or you want to make sure they never do), there are concrete steps you can take. This guide covers the most important improvements, from DNS records to message style.

Step 1: Set up authentication records (SPF, DKIM, DMARC)

These three DNS records are the foundation of email deliverability, and for Gmail they aren't optional. Since 1 February 2024, Google requires everyone sending to personal Gmail accounts to set up SPF or DKIM, and requires SPF, DKIM and DMARC from anyone sending more than 5,000 messages a day to those accounts. Google's own advice is to set up all three whatever your volume. Yahoo publishes similar requirements.

SPFLists which mail servers are allowed to send email from your domain
DKIMAdds a digital signature to every email, so a receiving server can confirm the message really came from your domain and wasn't altered on the way
DMARCTells servers what to do with email that doesn't pass authentication. A message passes the DMARC check when either SPF or DKIM passes and the domain that passed matches the domain in the From address

See SPF, DKIM & DMARC for email senders for a detailed explanation.

If Chykalophia set up your email platform, these records are likely already configured. If you're not sure, ask us to check.

Step 2: Use a professional email platform

If you're still sending from a free Gmail or Hotmail address, switching to Google Workspace or Microsoft 365 with your own domain is the single biggest improvement you can make.

Both platforms give you the tools to meet the mail providers' sender requirements properly (including DKIM signing for your own domain) and both publish their own setup instructions for SPF, DKIM and DMARC.

See Why not use a free Gmail/Hotmail for business? and Professional email options compared.

Step 3: Send from a consistent address

Spam filters value consistency. If you send from a different address or domain each time, you build no reputation. Pick one address (or a small set of addresses) and stick to it.

Step 4: Keep your email list clean (for bulk email)

If you send to a large list (a newsletter, marketing campaign, or automated notifications), list hygiene matters. Remove hard bounces and unsubscribers promptly, and re-engage or remove inactive contacts. See List hygiene for the full habits, plus the extra Gmail and Yahoo rules for bulk senders.

For bulk or marketing email, use a dedicated service (Mailchimp, Klaviyo, etc.), not your regular inbox. See Transactional vs marketing email.

Step 5: Make your emails look legitimate

Even with perfect DNS setup, message content matters. The first list below is our own judgement about what reads badly rather than a published rule, but we steer clients away from all of it:

ALL CAPS and strings of exclamation marks, especially in subject lines
Tired sales language: "FREE!!!", "Earn money fast", "Urgent"
Very image-heavy emails with little text
Vague subject lines

These next ones are rules the mail providers actually publish, so they matter more:

Rules the mail providers publish

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Don't mislead people with your subject line, headers or display name. Google says these should accurately represent who you are and what the message contains. Don't start a subject with "Re:" or "Fwd:" unless it really is a reply or a forward, and don't put sales copy in the sender name.
Keep links visible. Recipients should be able to tell where a link goes, and using HTML or CSS to hide content can get a message marked as spam.
If you send HTML, format it to HTML standards, and format the message itself to the standard internet message format (RFC 5322). Any decent email platform handles this for you.
Give people an easy way to unsubscribe from marketing email. Above 5,000 messages a day to personal Gmail accounts, marketing and subscribed messages must support one-click unsubscribe and carry a clearly visible unsubscribe link in the body.
Include your physical postal address in marketing email. In the US this is the law: the FTC's CAN-SPAM rules require a valid physical postal address, an accurate subject line, and a clear explanation of how to opt out, and opt-outs must be honoured within 10 business days. Other countries have their own rules, so check what applies where your recipients are. This is general information, not legal advice.

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Step 6: Check whether your domain is on a blocklist

If you've had deliverability problems for a while, your domain or mail server IP might be listed on a blocklist. Use a free tool like MXToolbox to check.

If you are listed, each blocklist has its own delisting process. This takes time but is fixable.

Step 7: Build up sending volume gradually

If you've just registered a new domain, or you're about to start sending a lot more than usual, don't jump straight to your target volume. Google's own guidance is to start with a low volume to engaged users and increase it slowly, to send at a consistent rate rather than in bursts, and to avoid sudden spikes. It gives suddenly doubling your previous volume as an example of what can get you rate-limited or damage your domain's reputation. The more you send, the more slowly you should ramp up.

Watch what comes back as you go. If messages start bouncing or being deferred, reduce the volume until the error rate drops, then increase slowly again.

Website form emails have their own setup

If your website contact form or order confirmation emails are going to spam, that's a separate issue from your personal email. See Email sent from your website explained and What is SMTP?.

Step 8: Use a reputable transactional email service for automated emails

If your website sends automated emails (order confirmations, password resets, booking notifications), use a dedicated transactional email service like Postmark, Mailgun, or SendGrid rather than routing through your regular email server. These services are purpose-built for reliable delivery of automated messages.

How to check your current setup

Chykalophia can audit your email configuration and tell you exactly what's set up and what needs attention. You can also use:

MXToolbox: check MX records, SPF, blocklist status
Mail-tester.com: send a test email and get a spam score with specific recommendations
Google Postmaster Tools, if you send any real volume to Gmail users. Google measures your spam rate here and requires senders to keep it below 0.3%, so it's the one number worth watching

Common questions

Someone told me my email is going to their spam. What's the fastest fix?

Ask them to mark your email as "Not spam" and add your address to their contacts. This is an immediate fix for that one person. For a long-term fix, check your SPF, DKIM, and DMARC records.

My emails work fine for most people but one company never receives them. Why?

That company likely has strict corporate spam filtering. Ask them to add your address to their safe senders, or ask their IT admin to allow your domain. See Your recipient's organization has strict spam filtering.

I haven't changed anything but my deliverability got worse. What happened?

Deliverability can change for external reasons. Your sending IP might have appeared on a new blocklist, or a mail provider updated their spam rules. Contact Chykalophia to investigate.

Does using a branded domain (yourbusiness.com) automatically improve deliverability?

It helps: a custom domain with proper authentication records is more trustworthy than a free address. But authentication records (SPF, DKIM, DMARC) still need to be set up correctly.