think I've got the DNS server in a twist... how can I check?

[#1]

Hi there
Started setting up my DNS records last night and after reading the guidance made several entries and then changed them because I decided that I'd read the guidance wrong in the first/second/third place.
Basically Ive entered:
mydomain.co.uk.      A                        x.x.x.x (static)
                                MX            1      mydomain.co.uk
www                        CNAME            mydomain.co.uk
Does this final configuration appear correct?  ( I did put an A entry for smtp.mydomain.co.uk but removed it because when I did a DNS check externally, I had done something wrong (not a FQDN I think) and ended up with smtp.mydomain.co.uk.mydomain.co.uk so I am hoping that it is now correct.
Having read on another thread that someone had got the server in a twist making too corrections in a short space of time is there any way I can check it to ensure everything is well and that I am just waiting for everything to propagate?  The reason I ask is because whilst externally I can search and get a result for the cname associated with my domain, mydomain.co.uk is not resolving and is returned as no records.
Lastly, reverse look up on my static IP is pointing to myusername.plus.com rather than mydomain - will this come with time once everything has propagated or does it need to be changed by PN?
Any help is greatly received... thanks

[#2]

for your reverse dns you need to raise a ticket and add proof that you own the domain.
your mx record should be something like mail. rather than the same as the A record.

[#3]

Hi there
Thanks for your advice.
The domain is hosted by PN so shouldn't they know that already?  Should I still raise a ticket?
Oh! wrt the mx record... so should be nothing in the left field and smtp.mydomain.co.uk. (fully qualified) in the right field? and should there be a corresponding A record to go with it?

[#4]

Hi,
Your records look OK now but you'll need to allow time for things to propagate.
Give me a nudge once they have and I'll sort your reverse DNS out for you.

[#5]

Hi Bob
Thanks for checking.  I shall wait and see then get back to you about the reverse DNS.