Why WordPress email often fails #
WordPress sends email (Contact Form notifications, WooCommerce order confirmations, password resets) using PHP’s built-in mail function by default. This function sends from the server’s local mail configuration, with no authentication and often with a from address that doesn’t match the server’s domain. Most receiving mail servers treat messages from unverified senders as spam or reject them outright. This is why “WordPress isn’t sending emails” is one of the most common WordPress problems: the emails are going out, they’re just not arriving.
What SMTP is #
SMTP stands for Simple Mail Transfer Protocol. It’s the standard protocol for sending email. When you configure WordPress to use SMTP instead of PHP Mail, you’re connecting it to an authenticated email sending service that receiving servers recognize and trust. The email leaves WordPress via an account with a verified identity, a valid domain, and proper authentication records, so it reaches inboxes instead of being filtered.
SMTP configuration in WordPress is typically handled by a plugin (WP Mail SMTP is the most widely used). You connect the plugin to a Transactional Email service (Mailgun, SendGrid, Postmark, or a standard mail account like Gmail SMTP), and from that point all WordPress emails route through that service.
SPF and DKIM #
SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) are DNS records that tell receiving mail servers “this server is authorized to send email on behalf of this domain.” Without them, even SMTP-authenticated emails from reputable services can be filtered as suspicious, because the receiving server has no way to verify the domain is legitimate. Most Transactional Email services include instructions for setting up SPF and DKIM records during configuration.
How this connects to Loupely captures #
Loupely’s Email Delivery capture records whether WordPress’s wp_mail function was called, and whether it returned success or failure. When wp_mail returns false, the mail transport failed: this is almost always the PHP Mail issue described above, and the fix is SMTP. When wp_mail returns success but emails still don’t arrive, the failure is downstream (spam filtering, missing SPF/DKIM), and that’s outside Loupely’s capture layer. See Contact Form Not Sending Emails and WooCommerce Order Emails Not Sending for the diagnostic paths.