Solved at 10am this morning (Thanks to @EduTech again). The Smarthost was pointing at the DAG Group IP (Which I changed on Friday afternoon, as the DAG group caused more woes than not receiving mail).
The adaptor labelled as 'External' connected to the ISA server for Client access only, the receive connectors were pointing at the external address (this confused me, but then I removed the DAG group address on Friday morning (checked my notes!)).
I started receiving NDR's saying that the host was not available by 9am this morning.
Thanks for all your pointers over the last couple of days!
The initial problem of poor owa performance (and the non receiving of external emails) was caused by the DAG group and the send/receive connectors being on the same adaptor.
Since 12 I've had no calls about email - first time since I started and it seems the problem is solved, as well as my understanding of exchange 2010 becoming far more advanced!
Thanks to all again!
Pleased to hear everything is back to normal for you now. Monitor and Ensure any errors are now resolved with Exchange ;-) Event Log should start to be a bit happier with you now that is sorted.
Originally Posted by Mr.Ben
Happy Days! Enjoy the rest of your week sir.
16gb for Exchange and you're worried? Wow, thank god for Zimbra! For *moments* today I was considering suggesting a move to Exchange!