I am having problems with Exchange.
We are getting problems in receiving delayed emails from certain clients.
If I view the message headers then I see that the hop before us was received at (for example) 9:15am and then our exchange server received it at 13:13.
I have been able to get a couple of people to send in any error messages that they receive
the mail system : Host or domain name not found. Name service erro for name=alchemydirectmedia.com type MX: host not found, try again
There was an SMTP communication problem with the recipiant's email server
It's always the same clients that get delays.
If I use my home account to send a mail it arrives almost instantly.
I have spoken to my ISP and they tell me that they do not see any problems
I have spoken to the hosting company that hosts our websites (the MX record is configured to route email to our static IP address, this has been set up for a couple of months) and they are happy that the DNS is all correct.
Where should I start to look?