Hi, This is a bit of an open question, but I need some help on where to start looking.
We seem to have issued receiving emails from different people. Emails mostly come in fine but randomly emails seem to get lost when being sent to us, with no error. The same person can email us one day and then the next the email wont arrive, Also we sometimes need to send an email to the person and if they reply rather than type a new email the email arrived fine.
Sorry, I know its lacking information but a pointer in the right direction would be good. Our domain is cmp.org.uk.