If your emails are landing in clients’ spam folders, or someone is sending fake emails that look as if they come from your domain, the fix usually starts with three DNS records: SPF, DKIM and DMARC.
Optinexs sets up and checks these records for UK businesses, remotely, and plans the DNS side of email migrations so nothing goes missing when you change provider.
Signs your email setup needs attention
- Quotes and invoices are going to clients’ spam or junk folders.
- You get bounce messages for emails that should have been delivered.
- Clients have received emails from your domain that you did not send.
- Problems started after changing email provider or moving to Microsoft 365.
- Your website, CRM, newsletter or invoicing tool sends email using your domain name.
SPF, DKIM and DMARC in plain English
- SPF lists the services allowed to send email for your domain, such as Microsoft 365 or your website.
- DKIM adds a digital signature to each email, so the receiving server can confirm it was not altered and really came from you.
- DMARC tells receiving servers what to do with email that fails those checks, and sends you reports showing who is sending as your domain.
Why it matters now
Since 2024, Google and Yahoo have required SPF, DKIM and DMARC from bulk senders, and Microsoft introduced similar rules for Outlook.com in 2025. For everyone else, mailbox providers still use these checks when deciding what goes to spam. They also make it much harder for criminals to impersonate your business: phishing was the most common attack on UK businesses in the government’s Cyber Security Breaches Survey 2025/26.
What we do
- Audit. We check your current DNS records and list every service that sends email as your domain.
- Fix SPF. One correct SPF record that covers all your senders and stays within the technical limits.
- Enable DKIM. For Microsoft 365 and any other service that supports it.
- Publish DMARC carefully. We start in monitoring mode, read the reports, and only tighten the policy once genuine email is passing.
- Check and report. We confirm the results and explain them to you in plain English.
Moving email to Microsoft 365?
Most email problems after a migration come from DNS. We lower record lifetimes before the move, switch your mail records only after mailboxes have been copied, and update SPF and Autodiscover so phones and Outlook connect to the new service. See our Microsoft 365 migration and consultancy service.
Frequently asked questions
Will changing DNS records interrupt our email?
Not when the changes are planned. We make them in a set order and check results before tightening anything, so genuine email keeps flowing.
Is DMARC worth it for a small business?
Yes. It costs nothing to publish, helps your email reach inboxes, and makes it harder for anyone to send fake emails using your domain.
What access do you need?
Access to wherever your domain’s DNS is managed, usually your domain registrar or hosting provider. We can work alongside you if you would rather not share a login.
Get your business email checked
Book a free consultation and tell us what is happening with your email. You can also email info@optinexs.com.