Email deliverability basics: make sure your business emails arrive

By Axyra Nova Editorial · 27 September 2026 · 5 min read · Marketing and SEO

A booking confirmation that lands in spam is worse than no confirmation at all. The customer thinks something went wrong, calls to check or books elsewhere. The same is true for quotes, invoices, password resets and newsletters. If your emails do not reach the inbox, your business quietly loses customers.

Email deliverability is the practice of making sure your emails arrive where they should. This guide explains the basics in plain terms, so you can check your own setup or brief someone to fix it.

Why emails go to spam

Mailbox providers such as Gmail and Outlook try to protect their users from unwanted and fraudulent mail. They look at signals such as:

• Whether the sender can prove they are allowed to send from that domain.
• The sender's history: do people open, reply to or mark these emails as spam?
• The content and formatting of the message.
• How much mail is sent and how suddenly volumes change.
• Whether recipients asked to receive the mail and can easily stop it.

Most deliverability problems come from missing authentication, poor sending habits or both.

Step 1: Send from your own domain

Emails from a free address, such as a generic webmail account, look less professional and give you less control. Use an address on your own domain, such as hello@yourbusiness.com, through an email provider that supports proper authentication.

If your website sends emails, such as contact form notifications or order confirmations, make sure it sends through a proper email service rather than the web server's default mail function. Many hosting environments send mail in ways that are often filtered.

Step 2: Set up SPF, DKIM and DMARC

These three records, added to your domain's DNS settings, help prove your emails are genuine:

• SPF lists the services allowed to send email for your domain.
• DKIM adds a digital signature to each email, which receiving servers can verify.
• DMARC tells receiving servers what to do with emails that fail the checks, and can send you reports.

Your email provider will give you the exact values to add. If DNS records are new to you, Cloudflare's learning centre explains how DNS works in plain language. Google's email sender guidelines explain what Gmail expects from senders, including authentication requirements that apply to bulk senders.

A common mistake is having more than one SPF record, or forgetting to include a service, such as a newsletter platform or booking system, that sends on your behalf. List every service that sends email from your domain before editing the records.

Step 3: Only email people who want to hear from you

For newsletters and marketing emails:

• Collect addresses with clear consent.
• Explain what people will receive and how often.
• Never buy email lists.
• Remove addresses that bounce.

For outreach to businesses, follow the rules that apply in each country and keep messages relevant and infrequent. Our guide to ethical cold outreach covers this in detail.

Step 4: Make unsubscribing easy

Every marketing email should include a clear, working unsubscribe link. Honour requests promptly. People who cannot easily unsubscribe often mark emails as spam instead, which harms your reputation with mailbox providers.

Step 5: Write emails like a person

Content matters less than authentication and sending habits, but it still plays a part:

• Use a clear, honest subject line.
• Avoid excessive capital letters, exclamation marks and spammy phrases.
• Keep a sensible balance of text and images.
• Include your business name and a physical address where required.
• Make sure links point to your own domain or well-known services.

Step 6: Warm up new domains and tools

If you start sending from a new domain or a new email tool, increase volume gradually. A brand new domain that suddenly sends thousands of emails looks suspicious. Start with your most engaged contacts and build up over a few weeks.

Step 7: Test before you send

Before a campaign or after changing your setup:

• Send test emails to accounts on different providers.
• Check whether they arrive in the inbox, promotions tab or spam.
• View the message headers to confirm SPF, DKIM and DMARC pass.
• Click every link.

Many email providers and free tools can check your DNS records and show whether authentication is set up correctly.

Transactional versus marketing email

It is often worth separating the two:

• Transactional emails are triggered by an action: a booking, an order, a password reset. They are expected and important.
• Marketing emails are newsletters and promotions.

Some businesses send them through different services or subdomains, so a problem with a marketing campaign does not affect booking confirmations.

A worked example

A small salon noticed that customers kept calling to ask whether their online bookings had gone through. Testing showed booking confirmations landing in spam for several email providers.

The cause was simple: the booking system sent emails "from" the salon's domain, but the domain had no SPF entry for the booking system and no DKIM signature. The salon's web developer added the booking system to the SPF record, set up DKIM using the values from the booking system's settings, and added a basic DMARC record to receive reports.

After the change, test confirmations arrived in the inbox, and the calls asking whether bookings had worked became rare.

Monitoring over time

Deliverability is not a one-time setup. Keep an eye on:

• Bounce rates and spam complaints in your email tools.
• DMARC reports, which show who is sending email using your domain.
• Customer comments about missing emails.

If you use Gmail heavily, Google's Postmaster Tools can show reputation data for bulk senders.

Where this fits with your website

Contact forms, booking systems and shops all send email. When you build or fix a website, test every email it sends. Our guide to contact forms that convert explains how to test form notifications, and our WooCommerce setup guide covers order emails.

How Axyra Nova helps

Axyra Nova checks the email setup behind small business websites as part of its site reviews and flags missing authentication records, giving sellers a clear, fixable problem to offer help with. See the features page.

Frequently asked questions

Do I need SPF, DKIM and DMARC?

For any business that sends email from its own domain, yes. They are now expected by major mailbox providers, especially for higher volumes.

Why do my emails go to the promotions tab?

Gmail's tabs sort mail by type. Promotional content often ends up there even when deliverability is fine. It is different from spam.

Can my website's contact form cause deliverability problems?

Yes. Forms that send through the web server without authentication are often filtered. Connect them to a proper email service.

How do I know if my setup is working?

Send test emails to several providers and check the message headers for passing SPF, DKIM and DMARC results.