Submissions using @yahoo.com not working

I just discovered while testing my contact form that submissions left using email addresses ending in @yahoo.com are not going through. The contact form seems to complete, and there are no error messages provided upon submitting the form, but the forms never reach me. Not any of my folders.

I have tested with email addresses I am certain are not valid, and so long as they end in @live.ca, hotmail.com, gmail.com, etc, they go through.

Is there something in the settings of the form I can change so that all submissions will come to me? I do not wish to narrow my client base based upon which email accounts they use when attempting to contact me.

Thank you in advance!

https://wordpress.org/plugins/cforms2/