We have one particular domain which has 3 MX preferences 10 15 and 20
All mail for this domain is being queued at present on my exchange 2k3 server for this domain, then after the default number of tries sends users 4.4.7 NDR
firstname.lastname@example.org on 15/10/2004 11:05
Could not deliver the message in the time limit specified. Please retry or contact your administrator.
However after running an nslookup I can setup an smtp session on the MX20 preference.
I can't find a setting anywhere within exchange 2k3 that forces it to try more than 2 mx preferences.