Contact form entries not showing in WordPress admin: why

Check these, in order

1. Does your plugin store entries? Contact Form 7 needs the separate Flamingo add-on. WPForms keeps entries only in its paid versions. If nothing was stored, nothing can appear — and old submissions can't be recovered from WordPress.
2. Is a filter on? Entries lists usually filter by form, status or date. Reset them.
3. Were they marked as spam? Look in the spam view. Aggressive spam checks catch real messages too.
4. Can your role see them? Entries contain personal data, so plugins limit who may read them. An editor account often can't.
5. Was it ever submitted? A JavaScript error, a caching plugin serving a stale security token, or a validation error the visitor didn't notice can stop a submission before it's saved.

Where Mailbag keeps them

Mailbag Contact Form saves every entry before it sends anything, so an entry exists even when the email failed. They appear under Mailbag → Entries for users who can manage options — administrators, by default; a developer can change the capability with a filter. The menu shows how many are unread.

Entries caught as spam are kept apart under Spam with the reason — honeypot, too fast, too many from one address, or a CAPTCHA verdict — for 30 days, at most 1,000 of them, so a real message filed there by mistake can still be found and read.

If the visitor saw an error

When Mailbag couldn't save an entry, it still tries to email the whole message with a line saying it couldn't be stored, and a notice on Mailbag's screens tells the administrator that the table needs attention. If both fail, the visitor is told plainly that the message wasn't sent — never a false “thank you”.