The short answer
A form can work perfectly and the email can still vanish, because the message is filtered as spam or rejected for failing sender checks. Look in spam and any alternate address first, then test with a different recipient. The durable fix is sending form emails through an authenticated mail service with SPF, DKIM and DMARC set up for your domain.
Two steps, not one
When someone presses Send, two separate things have to succeed. First the website must accept the form and hand a message to a mail system. Second the receiving mailbox must accept that message and put it somewhere you will see it. The success message on screen only reports the first step.
Almost every case of 'the form works but no emails arrive' is a failure in the second step, or in the handoff between the two. That is why clicking Submit again and again does not help. It is also why the site can be perfectly healthy while you lose enquiries.
The usual reasons, ranked by how often they happen
| Cause | What it looks like | Who fixes it |
|---|---|---|
| Landed in spam or junk | Test messages show up there, or in a promotions tab | You, then us for a permanent fix |
| Failed sender authentication | Mail never arrives anywhere, or only to some providers | Us and whoever manages your domain's DNS |
| Default web server mail | Intermittent delivery, worst with Gmail and Outlook addresses | Us, by switching to a proper mail service |
| Mailbox full or rejecting | Other mail to that address bounces too | You or your mail provider |
| Wrong recipient address | A typo or a person who left | Us, on your request |
| Plugin conflict or error | Form shows an error, or entries save but no email is triggered | Us |
Why authentication matters: SPF, DKIM and DMARC
Email was designed with almost no way to prove who sent a message. Anyone can type your address into the From line. To fight that, receiving providers now check three things.
SPF is a list in your domain's DNS of the servers allowed to send mail for you. DKIM adds a digital signature to each message that the receiver verifies against a public key in your DNS. DMARC ties them together: it tells receivers what to do when a message claims to be from your domain but fails the checks, and sends you reports. Its policies run from none, which only monitors, to quarantine and reject, which ask receivers to hold or refuse failures.
These are no longer optional for reliable delivery. Google's sender guidelines say all senders must authenticate with SPF or DKIM, and that senders of 5,000 or more messages a day to Gmail accounts need SPF, DKIM and DMARC, with the From domain aligned. A small business sends far fewer, but the same providers use these checks as a trust signal for everyone.
The classic trap: the form sends email 'from' your own address, such as info@yourdomain.com, through the web server's default mail. The server is not on your SPF list and nothing is signed, so Gmail and Outlook treat it as a forgery and quietly bin it.
SMTP versus the default mail
Out of the box, WordPress hands form emails to the web server's built-in mail function. That has no sender reputation and no signature, and many hosts limit or block it. A better setup sends form emails through SMTP, which is simply a proper, logged-in connection to a real mail service such as Google Workspace, Microsoft 365 or a dedicated transactional email service.
With SMTP the message leaves from a server that is on your SPF list, can be signed with DKIM, and produces a log you can read. If something fails, there is a record of exactly where. That log is the difference between guessing and knowing.
How to test properly
- 1Submit the form yourself using an address at a different provider from the recipient. If the recipient is a Google Workspace mailbox, use a free Outlook or Yahoo address as the sender, and the other way round.
- 2Check the inbox, the spam or junk folder, and any promotions or other tab. Search for the subject line, since a message may be filed away by a rule.
- 3Check the form's own entry list in the site's admin if it saves entries. If an entry exists but no email arrived, the form works and delivery is the issue.
- 4Test every recipient on the form, not only the first. A second address with a typo fails silently.
- 5Wait ten minutes before concluding a message is lost. Some providers delay messages from unfamiliar senders.
- 6Repeat the test on a different day. A pass at lunchtime and a fail overnight points to rate limits or a queue.
Do not test by submitting the form many times in a row. Repeated identical messages look like spam, and can push your domain's reputation down for real enquiries.
How a form should be configured
- Send through SMTP or a transactional mail service, not the server's default mail.
- Use a From address on your own domain, set up and authenticated, plus a Reply-To set to the visitor's address so you can answer with one click.
- Save every entry in the site as well as emailing it. Then a delivery failure never loses a lead.
- Send to at least two recipients if the enquiries matter, and make sure neither is a personal mailbox that may be left unattended.
- Add a spam check that does not hide real people, such as a hidden field or Cloudflare Turnstile.
- Show an honest error message if sending fails, so the visitor can phone you instead.
A worked example
Example: Three weeks of silence
A landscaping company notices that enquiries dropped from about ten a week to two. The owner tests the form and gets a 'thank you', but no email. A search of spam finds the test message under 'junk'. The form saves entries in the site as well, and there are forty-one of them from the last three weeks, none emailed. The cause: form mail was sent from info@theirdomain.com through the server's default mail, with no SPF entry covering that server and no DKIM. After we switch to SMTP with a Google Workspace mailbox and set up SPF, DKIM and a DMARC policy in monitoring mode, test messages arrive in the inbox within a minute. The forty-one saved entries are exported and answered. The lesson is that saving entries turned a disaster into an inconvenience.
When to ask us
Ask as soon as you suspect enquiries are missing, and before you change any DNS records yourself. A wrong SPF edit can break all of your company email, not only the form.
Send us the page address of the form, the exact time and the email address you used to test, the recipient address that should have received it, whether the message appeared in spam, and a screenshot of any error text. If the form's entries list shows submissions that never arrived, say how many and since when. File one request through the support form. For the wider picture of how your domain and mail connect, read email and your domain.
