were is email support?

I urgently need confirmation that e-mails have been sent to me.  Last week I knew of 1, today there is a claim that I did not answer 2 more.

They are from 2 different people at same location.  With the 1 have received mail before and after the missing date, the other I have never had any emails from that person.  Prior to this I have never had problems with emails to or from that server.