No, as long as the email is not determined to be spam, then the email is sent. This plugin has no moderation features for emails.
You could add that to the feature request section, but not something I’m planning on adding any time soon.
You might be able to configure something using Gravity Forms plus the Gravity Forms extension for my plugin:
https://stephensherrardplugins.com/plugins/pta-member-directory-gravity-forms/
Gravity Forms will save all form submissions and you could set it so that it does NOT send an email to the recipient. But, I’m not sure if you can then go into a submission and force it to send at a later time. It doesn’t have any built-in kind of moderation either (that I know of).
None of the contact forms that I know about have that feature, as that is more of a feature of a forum (bulletin board) than it is for a contact form. Contact forms are meant to send emails immediately, so they usually only have some type of spam protection against bots and other spammers.
