Documentation

Test MX Record

• Options: Yes / No
• Default: Yes 
• Description: When set to Yes, the plugin checks if the email address’s domain has a valid MX record in DNS, ensuring the domain can receive emails. This adds an extra layer of validation but may slightly increase processing time due to DNS queries. Results are cached system-wide (default 15 minutes, admin-controlled) to keep things fast. Set to No to skip this check and speed up form submissions, relying only on format validation.

Silent Mode

• Options: Yes / No
• Default: Yes 
• Description: When set to Yes, the plugin operates in silent mode, meaning it won’t display error messages to users if validation fails (e.g., “Invalid email address”). The form submission will still be blocked, but attackers won’t get feedback about why, making it harder for them to probe your form’s logic. Set to No to show error messages, which can be helpful for legitimate users who need to correct their input.

Whitelist Email

• Type: Repeatable (add as many entries as needed) 
• Field: Email Address *
• Description: Enter a specific email address (e.g., This email address is being protected from spambots. You need JavaScript enabled to view it.) to bypass validation checks. Whitelisted email addresses will be accepted by the plugin, even if they fail other validation tests (like format or MX record checks). Use this to ensure trusted senders can always submit forms without being blocked. You can add multiple email addresses by using the repeatable field.

Blacklist Email

• Type: Repeatable (add as many as needed)
• Field: Email Address *
• Description: Enter a specific email address (e.g., This email address is being protected from spambots. You need JavaScript enabled to view it.) to block it from being used in your contact forms. Blacklisted email addresses will be rejected, even if they pass other validation checks (unless they’re also whitelisted, in which case the whitelist takes priority). Add as many email addresses as needed to prevent known spammers or troublemakers from submitting forms.

Whitelist Domain

• Type: Repeatable (add as many as needed)
• Field: Domain *
• Description: Enter a domain (e.g., yourcompany.com) to bypass validation checks for all email addresses from that domain. Whitelisted domains will be accepted, even if they fail other validation tests. This is useful for allowing all emails from a trusted organization. You can add multiple domains using the repeatable field.

Blacklist Domain

• Type: Repeatable (add as many as needed)
• Field: Domain *
• Description: Enter a domain (e.g., shady.com) to block all email addresses from that domain. Blacklisted domains will be rejected, even if they pass other validation checks (unless they’re also whitelisted, in which case the whitelist takes priority). Use this to prevent entire domains known for spam or abuse from submitting forms. Add as many domains as needed.

Blacklist MX

This is a unique configuration, allowing an administrator to block an MX using FQDN or partial hostname. FQDN is the full hostname of the MX/mail server. Partial hostname deserves an example:

Additional Notes

• Validation Limitations: Contact - Valid Email cannot verify if an email address is real or actively in use—only that its format is valid (using PHP’s filter_var function) and, if enabled, that the domain has an MX record in DNS. For example, it can confirm that This email address is being protected from spambots. You need JavaScript enabled to view it. has a valid format and that example.com can receive email, but it can’t check if This email address is being protected from spambots. You need JavaScript enabled to view it. is an actual mailbox.
• Whitelist Priority: If an email address or domain is on both the whitelist and blacklist, the whitelist takes precedence, and the email will be allowed.
• Performance Tip: If you enable the MX record check, results are cached system-wide (default 15 minutes, admin-controlled) to reduce DNS queries and keep form submissions fast, especially on high-traffic sites.