Email deliverability is about whether your messages reach inboxes reliably. For a business website, this affects contact form notifications, password resets, invoices, booking confirmations, and customer replies.
Use the Right Sender
Website mail should usually come from an address on your own domain, such as [email protected]. Put the visitor's address in reply-to, not in the sender field.
Set SPF
SPF tells receiving servers which systems are allowed to send mail for your domain. Include your mail provider and any service that legitimately sends on your behalf.
Enable DKIM
DKIM signs outgoing messages. Your email provider will give you the DNS record. Add it and verify it inside the provider's dashboard.
Add DMARC
DMARC builds on SPF and DKIM. Start with a cautious policy if you are unsure, then tighten once you understand every service that sends mail for the domain.
Use SMTP for Websites
For WordPress and other CMS forms, authenticated SMTP is usually more reliable than basic PHP mail. Use a reputable SMTP service or your mail provider's SMTP settings.
If form mail is unreliable, check DNS authentication, SMTP settings, logs, and whether the message content itself looks spammy.
Authenticate Every Legitimate Sender
List the mailbox provider, website, CRM, invoicing and marketing platforms that send as the domain. Publish one SPF policy covering authorised infrastructure, enable DKIM signing at each provider and add DMARC for reporting and policy. Remove obsolete senders instead of continually expanding access.
Use Aligned, Real Addresses
Website forms should submit through authenticated SMTP or a transactional provider and use a sender address the system is authorised to send. Put the visitor's address in Reply-To rather than forging it in From. Monitor bounces and do not send to addresses that repeatedly reject mail.
Diagnose with Evidence
Keep the bounce, recipient, timestamp and message ID. Check SPF, DKIM and DMARC results in received headers and inspect provider logs. Inbox placement also depends on reputation, list quality, volume and content, so passing DNS checks is necessary but not a guarantee.
