Support » Plugin: Contact Form 7 » Validating Email Bug?

  • Resolved mizzinc


    I was alerted to emails being sent that are incorrect.

    For example foo@foo.c is accepted. Is this something you need to fix at your end or is there is interim solution you can provide?

    Thanks 🙂

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  • Does this need more clarification?

    It seems the issue is with domain suffix (.com, .co, .au). The email address is accepted if only one letter of the suffix is provided.

    For example domain.c, domain.u, domain.z

    The email address foo@foo.c should not validate.

    @takayukister – is this a bug?

    An incomplete email address is validated as correct.
    Example: foo@foo.c should throw an error, but its accepted.

    Plugin Author Takayuki Miyoshi


    Contact Form 7 uses is_email() to validate email address input. is_email() is a function defined in the WordPress core. The function only does a syntactical check for an email address, so it doesn’t matter to is_email() whether the domain used in the address exists at the moment or not. I don’t say it is a bug. That’s how the function is designed. If you want to validate email address in an existence-verification level, you’ll need to write code yourself.

    Thank you so much for taking the time to answer. Very helpful.

    Ive installed ‘Contact Form 7 Email Validation’ ( to assist where is_email() doesn’t.

    • This reply was modified 1 year, 3 months ago by mizzinc.

    It might be too late to reply on this question but I just shared my new finding here.

    Recently I have tried on a new third party email validator to validate the email coming from Contact Form7. It is called MailboxValidator Email Validator. From the plugin documentation, it extend the is_email() filter and helped to validate on more criteria, such as is the email is a valid email, disposable or free email.

Viewing 5 replies - 1 through 5 (of 5 total)
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