Hi,
This problem is driving me nuts....
My environment is as follows:
1 exchange 2010 sp3 server (virtual server on VMware ESXi) migrated from exchange 2003 during the end of 2012.The serves is using internal DB. and uses activesync with ISA server 2006 for webmail. Log DB and the main DB are connected as LUN's to the server on an iSCSI connection to a Netapp filesrver.
internal Users are using outlook 2010 & outlook 2013 in non-cached exchange mode while all laptop users and external users use Outlook 2013 and Outlook 2013 with cached exchange mode and HTTPS over RPC.
it has begun with one user who was constantly complaining that whenever he was connected to Outlook when outside the office with his laptop. He would sporadically receive and NDR mail when sending toanother internal email and also to external emails. The NDR's themselves do not contain the error report with any codes. here's one example:
Your message did not reach some or all of the intended recipients.
Subject: RE: Netgear mule
Sent:24/12/2012 23:58
The following recipient(s) cannot be reached:
*********** on 25/12/2012 00:00
None of your e-mail accounts could send to this recipient.
The same mail is then resent and it will either be received at the recipient side or the sender will get another NDR. The email address itself is correct.
I've asked the sender to check whether this happens also while connected to webmail and according to him, webmail access was slow but emails were sent successfully.
On a different occasion while he was getting the NDR's I asked him to connect to VPN and send again. the user then reported that he was able to send successfully.
this phenomenon almost always happens when he is outside the office, whether in the country or not.
It does not happen when he's inside the office.
up until now he was the only one complaining but recently I've learned that more users have this issue but not as often as he does. what these NDR's have in common to all the users complaining is that it happened when they are outside the office.
I've tried almost everything except to switch the user to a whole new mailbox: cleaning out the cached email in outlook (which is the most common solution for these NDR's), reinstalling outlook, remove and create a new outlook profile, adding x500 mail address to his user (thinking perhaps the migration from exchange 2003 to 2010 didn't work like it should), upgrade his outlook to 2013, etc.. But still the problem remains.
I do think it has something to do with slow networks... as when the user gets the NDR's he's also complaining that overall network speeds were very slow as well.
strangely enough, we have other external users from all across the globe who do not complain about this (that I know of)
So, the question is whether NDR's might be caused by very slow network speeds and whether something can be done in order to rectify it or might it be a problem with the user's computer (on a different computer from his home it works OK) Or is it something in the exchange 2010 or ISA server that needs to be reconfigured).
Please Help,
Amit