Solved

Exchange 2010 - No Inbound Mail, No Port 25, But Web Mail is fine?

Posted on 2013-01-28
6
511 Views
Last Modified: 2013-01-29
Hello Experts,

Looking to see if you can quickly help me find a resolution to my Exchange issue. Today, inbound mail to our domain name fails with "550 MTA inaccessible for too long"

Internal mail is fine, and sending outbound mail is fine.

Anyway, after initial troubleshooting using MXTOOLBOX and simple TELNET, I see that I cannot connect via port 25.

Any hints on where to begin?
I'm looking on a Sonicwall and this looks fine - Exchange service itself looks fine - I need some hints please.
0
Comment
Question by:ottobock
[X]
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
  • 4
6 Comments
 
LVL 8

Accepted Solution

by:
d0ughb0y earned 250 total points
ID: 38828956
For starters, who's your ISP. Might they be blocking it? I know that many do, for their Home-Service offerings.
0
 
LVL 10

Assisted Solution

by:JaredJ1
JaredJ1 earned 250 total points
ID: 38829171
Did your test telnet session happen from within the LAN or external?

From a computer on the LAN - attempt to telnet to the Exchange server on port 25.

e.g. telnet servername 25

If it gets a connection, then you know the server is listening on port 25 and the problem is likely to be the sonic firewall. It should have a NAT rule (or web forwarding) of TCP port 25 to your Exchange Hub Transport server.

Do you have any other mail appliance/scanning server that may sit between the sonicwall and Exchange? A Message filtering server, journaling appliance? Perhaps there is something in-between that is causing the problem.
0
 
LVL 7

Author Comment

by:ottobock
ID: 38831317
Hi, back to it today. Thanks for the ideas.

It could actually be something with the ISP - as there are 2 circuits coming in (1 fibre and 1 cable), and the cable is down. We're also checking on that...

Using TELNET, I tested within the LAN, and also external. Within the LAN, it's fine. Outside, it's not. I thought about the SonicWall too - I'll try and check into that.

Really, this issue is sort of difficult, because I'm only maintaining this network for a short time, and I don't really know all the configurations. Now, I just get the problems and have to dig through everything to try and help! It's proven to be a tough job! :-)

Anyway, if anyone has additional thoughts - I'd love to hear'em. Thanks!
0
Office 365 Training for Admins - 7 Day Trial

Learn how to provision tenants, synchronize on-premise Active Directory, implement Single Sign-On, customize Office deployment, and protect your organization with eDiscovery and DLP policies.  Only from Platform Scholar.

 
LVL 7

Author Comment

by:ottobock
ID: 38832050
I have done some more troubleshooting, and more and more, I think it can be a sonicwall configuration that I'm missing. Maybe someone can help (I hope).

LAN testing:
- TELNET mailserver.com 25 = OK

External Testing:
- TELNET mailserver.com 25 = fail
- TELNET mailserver.com 443 = OK
- MXTOOLBOX.com mailserver.com, SMTP test = Fail/ Timeout

There are 2 sonicwalls. 1 had the cable internet, the other a fibre internet. Since the cable was disconnected by the provider, I will have a tough time to test that angle further at this moment.

But is there a simple policy or route that I can add to the SonicWall on the fibre, even if it's not really secure, just to test this? When I ping mailserver.com, I get the IP of the sonicwall on the fibre circuit.

I hope this makes sense...
0
 
LVL 7

Author Comment

by:ottobock
ID: 38832059
I've also tried going line by line on both SonicWalls, under NAT Policies, and Firewall rules, and can't seem to find many differences which would apply here.

Another wrench in the chain... I just found a ESVA antispam server in the DMZ - of which I had no knowledge...

Ugh.
0
 
LVL 7

Author Comment

by:ottobock
ID: 38832604
Turns out is was the cable service indeed. Once re-established, the mail gateway came alive. Now I have to do some more digging on why this is configured this way ...

Thanks everyone!
0

Featured Post

SharePoint Admin?

Enable Your Employees To Focus On The Core With Intuitive Onscreen Guidance That is With You At The Moment of Need.

Question has a verified solution.

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

Learn to move / copy / export exchange contacts to iPhone without using any software. Also see the issues in configuration of exchange with iPhone to migrate contacts.
This article explains how to install and use the NTBackup utility that comes with Windows Server.
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 a mailbox database 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 Servers >> Data…

691 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