Why Business Emails Go to Spam: Causes and Fixes for UK Senders
Business emails go to spam mainly because the sender cannot be verified, the list is poor, or recipients mark messages as unwanted. Set up SPF, DKIM and a DMARC record for your sending domain, send only to people who asked to hear from you, and keep messages relevant. ProfileTree describes a missing DMARC record as a deliverability fault that no subject-line testing will fix.
Contents
- Why emails land in spam
- SPF, DKIM and DMARC in plain English
- How to check your set-up
- Set-up steps
- Other fixes
- Do not blame the subject line first
- Frequently asked questions
- Sources
Why emails land in spam
- The sender cannot be verified. Receiving systems check whether an email really comes from your domain. Without SPF, DKIM and DMARC records, they may distrust it.
- A poor list. Old, bought or unrequested addresses lead to bounces and complaints.
- Recipients mark it as unwanted. Too many emails are a common reason people unsubscribe or complain; one UK source reports 57% of UK consumers unsubscribe because of too many emails.
- A sudden jump in volume from a domain that normally sends little.
- Spammy content or broken links.
- Poor formatting on phones, which hurts engagement.
Business email in the UK is often hosted on Microsoft 365, so authentication matters for reaching business recipients.
SPF, DKIM and DMARC in plain English
| Record | What it does |
|---|---|
| SPF | Lists the services allowed to send email for your domain |
| DKIM | Adds a digital signature that shows a message was not changed on the way |
| DMARC | Tells receiving systems what to do when SPF or DKIM checks fail, and sends you reports |
All three are records set up in your domain’s settings. Your email platform and your domain provider have instructions.
Want a second pair of eyes? Clariti Digital can review your setup and show you what to fix first.
How to check your set-up
- Ask your email platform whether SPF and DKIM are enabled for your sending domain.
- Look up your domain’s DNS records with your domain provider, or a free record checker, and see whether SPF and DMARC records exist.
- Send a test email to a few different mailbox providers, including a Microsoft 365 address, and see where it lands.
- Read any DMARC reports once you have them.
Set-up steps
- Add an SPF record that includes your email platform and your normal mail service.
- Turn on DKIM signing in your email platform and publish the record it gives you.
- Publish a DMARC record. A common approach is to start in monitoring mode, read the reports and tighten the policy later. Confirm the steps in your platform’s documentation.
- Send from your own domain, not a free mailbox, when you send in volume.
Other fixes
- Clean your list: remove bounces and people who never engage.
- Send only to people who asked. See UK rules for emailing and texting customers.
- Send at a steady rate and not too often.
- Keep emails relevant and readable on a phone.
- Make unsubscribing easy, so people do not click spam instead.
For what to send, see email marketing for local businesses, and for whether text messages might suit you better, read email vs SMS marketing.
Do not blame the subject line first
Subject-line tests help once your emails reach the inbox. If they do not, fix authentication and list quality first.
Frequently asked questions
Why are my business emails going to spam?
Common causes are a sender that cannot be verified, a poor list and recipients marking messages as unwanted. Check your SPF, DKIM and DMARC records first.
What is DMARC?
A record that tells receiving systems what to do with emails that fail checks for your domain, and sends you reports about them.
Do I need all three records?
It is good practice to have all three, because receiving systems use them to decide whether to trust your emails. Follow your platform’s instructions.
How long does it take to fix?
Records can be added in minutes but changes can take time to spread, and reputation recovers gradually. Test after each change.
Can I send newsletters from my normal mailbox?
Not at volume. Use an email platform that signs messages for your domain, and set up the records.
Sources
- ProfileTree, Email marketing statistics: UK benchmarks for SMEs, checked 11 October 2026.
- Whito, UK email marketing mistakes report, checked 11 October 2026.
- Information Commissioner’s Office, Guidance and resources, checked 11 October 2026.
Sam, Editor at Clariti Digital.
Related guides
- Email marketing for UK local businesses: A simple email plan for local businesses.
- Email vs SMS marketing: How to choose between email and text messages.
- UK rules for emailing and texting: UK points to check before emailing or texting customers.
Need help with this?
Clariti Digital is a UK digital growth agency for established local businesses. We start with a diagnostic, then fix what holds back visibility, enquiries and trust. Call +44 7435 063827 or email sam@claritidigital.com.