Delivery to Gmail proves that one route worked; it does not prove the company domain accepted the same message. The business mailbox may use a different gateway, quarantine, transport rule or authentication policy.
Keep the form configuration stable while comparing two recipients with the same controlled message.
Run a fair recipient comparison
Send a uniquely labelled, non-sensitive test to the working Gmail address and the failing company address. Use the same form fields, From address and time window. Record both recipients and the exact submission timestamp.
Confirm that the form created notifications for both addresses. Conditional routing, a misspelled domain or an invalid field token can mean the company notification was never generated.
If the plugin stores entries, retain the test entry until the trace is complete.
Read the WordPress and SMTP evidence
Check a mail log that records the recipient, subject, time and result without exposing unnecessary message content. A WordPress success result normally means the message was handed to its mail transport; it is not final delivery evidence.
Then review the SMTP or transactional provider log. Look for the company recipient and note whether it was accepted, deferred, bounced, suppressed or never submitted.
A provider response code is more useful than changing the form plugin. Preserve the exact redacted response for the mail administrator.
Check the company mail gateway
Ask the authorised email administrator to search by recipient, timestamp, sender and message ID. The message may be in gateway quarantine even when it is absent from the user’s spam folder.
Review organisation-wide allow/block lists, transport rules, impersonation protection and attachment policies. A shared mailbox, alias or distribution group can also reject external senders or require membership.
Do not globally allow the website IP or disable anti-spam protection. Make the narrowest evidence-based rule change.
Verify sender authentication and alignment
The visible From domain should be authorised by the sending provider. Inspect the headers of the message that reached Gmail and check SPF, DKIM and DMARC results. A company gateway may enforce failures more strictly than Gmail appears to.
Use a domain mailbox as From and place the visitor address in Reply-To. Do not send as the visitor, because the website is not authorised to use Gmail, Outlook or a customer’s company domain.
If DNS must change, keep one valid SPF record and publish the provider’s exact DKIM selector. Allow for DNS propagation before judging a retest.
Inspect bounces and suppressions
Check the authenticated return-path mailbox and provider logs for a non-delivery report. Repeated historical bounces may place the company address on a suppression list, so later messages are discarded before a new SMTP attempt.
Confirm that the mailbox and domain are spelled correctly, active and within quota. If the recipient is an alias or group, test its underlying mailbox separately with approval.
Never remove a suppression without first fixing the reason it was created.
Separate routing from content
If a plain notification arrives but the normal one does not, compare links, attachments, subject wording and HTML structure. Security filters can quarantine executable attachments, password-protected files or suspicious URLs.
Do not evade filtering with obfuscation. Remove unnecessary risky content and use an approved secure file-transfer method when forms collect uploads.
Test both a normal business enquiry and any attachment workflow after the repair.
Prove delivery and monitor it
A complete verification shows the form entry, generated notification, provider acceptance and final company mailbox delivery. Capture the delivered message ID and authentication results.
Run a second test after any DNS or gateway change and confirm the Gmail route still works. Monitor delivery events without storing form contents longer than necessary.
Request urgent help when provider and gateway logs disagree or genuine leads are at risk. Share timestamps and redacted status codes, never mailbox credentials or customer submissions.