Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17


Exchange 2007 SP1 - Incoming external mail disappearing

Posted on 2009-04-05
Medium Priority
Last Modified: 2012-05-06

I am running Exchange 2007 SP1 on Windows SBS 2008 and it has been running smoothly for several months. Today, however, 2 things (presumably connected) happened:

(1) Incoming messages from external organisations/addresses are seemingly disappearing -- they are not delivered to recipients, and external senders don't get any kind of bounce message. Obviously this is very concerning since I don't know where those messages may have gone. Incoming messages from within the organisation *are* delivered fine, and outgoing messages sent "to the outside world" are also getting through. So it seems to affect only incoming messages from the Internet.

(2) Mobile devices are no longer syncing via ActiveSync properly. It just says "Connecting..." for a while and then eventually gives up. I also allow connections via IMAP, and same thing happens there. Strangely, though, I noticed that my mobile device has synced occasionally from time to time -- after about 2 or 3 hours of it just sitting there, I noticed that as a one-off it did manage to download (internal) messages. When I tried again straight afterwards, it got stuck at "connecting..." again.

I've restarted the whole server and run the Mail Flow Troubleshooter and Best Practices Analyzer. These don't appear to indicate anything different to normal.

The issue with the syncing made me wonder if perhaps the server is being slowed down by some kind of network traffic problem or other resource issue. I'm not aware of anything specific but not really sure how to diagnose these issues. (We are a company of only 4 people and I'm relatively new to Exchange and network admin.)

Thanks for any suggestions anyone has about a fix and/or things to look at!

Question by:MikeBarry09
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
LVL 32

Accepted Solution

gupnit earned 750 total points
ID: 24071792
Please goto and let me know the results, else the site would lead you to solution
Also read:
Nitin Gupta (gupnit)

Author Comment

ID: 24071864
Hi Nitin,

Thanks -- very useful. When I tried the ActiveSync simulation, the first steps worked fine, but then after a long wait it failed at testing http authentication methods, saying the operation timed out:

Exception Details: Message: The operation has timed out Type: System.Net.WebException Stack Trace: at System.Net.HttpWebRequest.GetResponse() at Microsoft.Exchange.Tools.ExRca.Tests.HttpAuthMethodsTest.PerformTestReally()

When I tried the inbound SMTP test, it failed checking that port 25 was listening/open, specifically giving the detail "The connection was established but a banner was never received".

Given that I've not changed anything in the configuration (and certainly haven't blocked port 25 via the firewall etc.) this seems to be consistent with a very slow Internet connection. A non-technical colleague who is physically on site (I am connecting via Remote Desktop) has reported that "the Internet in general seems extremely slow", so I checked on our ISP's service status page and it seems possible that some upgrade works they are doing could be the root cause. (They didn't bother notifying us in advance, of course.) However, I can currently access Remote Desktop without any noticeable slowness.

Does this behaviour seem consistent with a very slow/intermittent bandwith issue? If so, what will happen to the messages people are trying to send us -- will they just never be delivered, or will the sender's mail server in most cases keep trying to re-send it over a period of time? What concerned me most is that a test message I sent didn't bounce, so a sender may not know that their message couldn't be delivered. That could I guess just be the behaviour of my other ISP's (non-Exchange) mail server?


LVL 32

Expert Comment

ID: 24073870
Hi Mike,
I would call upon my Network Engineers to check the Network and devices like Firewall/Router/Switches, along with Bandwitdh tests on ISP. Also disable Internet usage for users and test.

Assisted Solution

Dave_Angel_Portsmouth earned 750 total points
ID: 24078062
Seams odd that only email is not getting through but you can RDP remotly.

It would be useful to know if incomming emails are unable to get to the server, or, they are arriving and being deleted.

1) Check your MX record, is some external DNS issue preventing external mail from reaching you. (do this from here
2) Are any non-exchange aware virus checkers operating on the exchange server (if so stop them immediatly)
3) Are any of your clients set up to use PST instead of OST files, or indeed any mobile devices not set to leave emails on the server. (try disconnecting all clients and sending emails to the server, add clients one by one)


Featured Post

Is Your AD Toolbox Looking More Like a Toybox?

Managing Active Directory can get complicated.  Often, the native tools for managing AD are just not up to the task.  The largest Active Directory installations in the world have relied on one tool to manage their day-to-day administration tasks: Hyena. Start your trial today.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

How to deal with a specific error when using the Enable-RemoteMailbox cmdlet to create a mailbox in the cloud-based service, for an existing user in an on-premises Active Directory.
One-stop solution for Exchange Administrators to address all MS Exchange Server issues, which is known by the name of Stellar Exchange Toolkit.
In this video we show how to create an Address List in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center. Navigate to the Organization >> Ad…
In this video we show how to create an email address policy in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.:  First we need to log into the Exchange Admin Center. Navigate to the Mail Flow…

704 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question