emails not working

Hi,

My problem is that my emails connected to my website are not working properly (sending but not receiving). My host is 123 reg and they have told me (via chat) that I had to change my MX servers to point to 123-reg servers (they had been pointing to wordpress servers). They gave me their numbers and I did this (I think).. but problem not resolved. Is there anyone at wordpress I can talk to/chat to to resolve this? Various people have been trying for weeks now! any help most appreciated…
thanks in advance