Email Active but contact form submissions do not come through

I recently went onto a vps last night and as of this morning when I test fill out contact forms on my website it says the usual thank you message etc however does not appear in my inbox. However when I send an email from my yahoo account to the website email address it comes through fine – so it is active & working – Do I need to work this out with my host or can I do something ont he vps optimized cpanel?

On my mail delivery reports when I search it comes up with the message & says message accepted (this is seprate from webmail)

However it frequently pops up with sending from a root & says the following
User 0 set for local_delivery transport is on the never_users list

I have no idea what to do! Any ideas would be very appreciated

Thank you