This is the diagnosis and fix, in the order that actually worked.

Step 1: Prove it's the mail, not the form

Before touching settings, I sent a test from the WordPress dashboard (WP Mail SMTP → Email Test). It failed. That one test splits the problem in half: the form plugin was fine; WordPress itself could not send mail.

The default WordPress mail path (PHP mail()) is the usual suspect on shared hosting — messages leave the server unauthenticated, and receiving mail servers treat them accordingly: spam folder at best, silent drop at worst.

Step 2: Send through a real mailbox instead

I created a mailbox on the domain itself (info@ at my hosting control panel) and pointed WordPress at it with the WP Mail SMTP plugin:

• Mailer: Other SMTP
• SMTP Host: the hosting mail server (mail.)
• Port / Encryption: 465 with SSL
• Authentication: ON, with the mailbox's username and password
• From Email: the same mailbox address, with "Force From Email" ON so plugins can't override it

Sent the dashboard test again. This time it arrived — in the inbox, not spam. But "it arrives" is not the same as "it's fixed."

Step 3: Authenticate the domain (the part most tutorials skip)

Authenticated SMTP gets the message out. Three DNS records are what convince Gmail and Outlook to trust it:

• SPF — a TXT record naming which servers may send for the domain.
• DKIM — the mail server signs each message; the public key lives in a TXT record (mine sits under a default._domainkey-style selector — your host's email panel will show you the exact record to publish).
• DMARC — a TXT record on _dmarc saying what to do with mail that fails the other two, and where to send reports.

My host's email panel has a "Email Deliverability" screen that shows all three records with a Valid/Invalid verdict each. All three read Valid before I stopped — that's the acceptance test, not "the test email arrived once."

Step 4: Test like an outsider

• Dashboard test to a Gmail address → arrived in Inbox.
• A real form submission end-to-end → arrived.
• Reply path sanity check: replies go to the domain mailbox, which I can actually read.

Four green checks. Only then did I consider it fixed.

What I do differently now

For three days that form was a hole in the site, and nothing — not the form plugin, not WordPress, not the host — told me. The lessons, in order of how much they cost me:

1. Test email on launch day, from the outside in. A form that "works" on screen proves nothing about delivery.
2. Turn on the form plugin's database storage. Mine was off, so the lost submissions left no trace anywhere. Storage is now on — if mail ever breaks again, the enquiries survive in the database.
3. SPF + DKIM + DMARC are launch tasks, not later tasks. They take ten minutes at the DNS panel and decide whether your mail exists.

A contact form is the whole point of a lead-generation site. Mine was decorative for three days. The fix took one sitting — once I knew where to look.

Masood Ahmad is the Editor of Dentist in Pico Rivera, a one-person lead-generation website he built, migrated and runs himself.