Exchange External mail not flowing

[local-lad-steve]

Hi, URGENT HELP NEEDED!

we have a client we look after at work that is having mail routing problems. Internal mail in fine, it is simply anything that is leaving the organisation or coming into the organisation.

I am pretty new to exchange and have been lumbered with this problem and am under pressure to get it fixed. below are the results of another engineers testing smtp port 25

 

Testing inbound SMTP mail flow for domain '[email protected]'.

The Microsoft Connectivity Analyzer failed to test inbound SMTP mail flow.

Test Steps

Attempting to retrieve DNS MX records for domain 'DOMAIN.com.au'.

One or more MX records were successfully retrieved from DNS.

Additional Details

 

 

Testing Mail Exchanger mail.DOMAIN.com.au.

One or more SMTP tests failed for this Mail Exchanger.

Test Steps

Attempting to resolve the host name mail.DOMAIN.com.au in DNS.

The host name resolved successfully.

Additional Details

 

Testing TCP port 25 on host mail.DOMAIN.com.au to ensure it's listening and open.

The port was opened successfully.

Additional Details

 

 

Analyzing SMTP Capabilities for server mail.DOMAIN.com.au:25

SMTP Capabilities were analyzed successfuly.

Additional Details

 

 

Attempting to send a test email message to [email protected] using MX mail.DOMAIN.com.au.

 

Delivery of the test email message failed.

 

Additional Details

 

The server returned status code -1 - The operation has timed out.

Exception details:

Message: The operation has timed out.

Type: System.Net.Mail.SmtpException

Stack trace:

at System.Net.Mail.SmtpClient.Send(MailMessage message)

at Microsoft.Exchange.Tools.ExRca.Tests.SmtpMessageTest.PerformTestReally

 

 

There have been multiple tests run, some email gets into the exchange server, but can take several hours. I have had an email from an engineer that is now on annual leave to tell me what he has tried to do, some of which is:

 

- Disable Antivirus services

- Enable POP3 and IMAP4 services

- Restarted MS Exchange AD topology and Information Store services

- Reboot server

- Disable Windows firewall private and Public profile

- Created new recipient connector

- Created new SNMP connector for port 587

- Changed FQDN of all recipient connectors From remote.DOMAIN.com.au to mail.DOMAIN.com.au and vice versa

- Changed remote server Ip addressed range to allow all connection for recipient connector

 

All have been tried and tested yet no joy. he suspects maybe MX hosting service provider issue where email gets delayed or dropped. but not sure where to go with this.

 

Any advise people?

 

thanks in advance!!

 

 

 

[EduTech]

Hey Mate,

 

Drop me an IM if you want and I'll give you a hand this morning... I could do with the domain and I'll do some digging and then try and guide you as to what to check.

 

SMTP Test:

 

 

Inbound Email seems to be coming in ok:

 

 

Outbound Email seems to be ok:

 

 

I must admit, when it's doing a reverse lookup on the IP address it is contacting a different domain to the one you have configured in your MX records and so that probably isn't helping things.

 

Thanks,

James.

Edited September 8, 2013 by EduTech

[local-lad-steve]

not sure if it helps, but if i do a tracert to the affected mail server it connects.

 

if i do it from the mail server back to my domain it times out.

 

Any further thoughts?

[Dos_Box]

Moving to Enterprise Software forum.

[local-lad-steve]

update: its taking upto 3 days for external email to route into the domain. having looked at the exchange server today, I found that disk space was down to 4%. BUT, surely if exchange doesn't allow for disk space to go below a threshold then internal mail would also stop working??

 

Also i found that there is a certificate issue. its looking for 'mail.domain.com.au' where as the certificate is 'remote.domain.com.au' could this be the issue?? if so, how do we go about fixing the certificate?? See attachment.....

 

Exchange is running on an SBS server 2008 and exchange is running on sp1 - I believe.

 

im in desperate need to get this resolved..any suggestions appreciated!!!!!!

 

thanks!!

[local-lad-steve]

James, I also got a successful test today for inbound email. 5 mins later I got a failed one. there is no consistency. is fails more often than I connects.

[local-lad-steve]

10 mins ago a test email was received into the administrator mailbox.

 

BUT, the following error has just occurred in the last few mins having run testing again:

 

" Attempting to send a test email message to [email protected] using MX mail.domain.com.au.

Delivery of the test email message failed.

 

Additional Details

The server returned status code -1 - The operation has timed out.

Exception details:

Message: The operation has timed out.

Type: System.Net.Mail.SmtpException

Stack trace:

at System.Net.Mail.SmtpClient.Send(MailMessage message)

at Microsoft.Exchange.Tools.ExRca.Tests.SmtpMessageTest.PerformTestReally() "

 

Has anyone see this before?

[local-lad-steve]

Further update:

 

I sent 8 test emails from my external email address to the administrator mailbox one after the other and labelled the subject line 1 to 8 as per email. within 2 mins, emails number 3 and 6 came through. after 10 mins, emails number 4 and 7 came through, then 12 mins later emails 1 and 2 came through.

 

bizarre behaviour.

 

can anyone suggest what might be causing this???

[EduTech]

What Priority are your MX Records, It is my understanding you only have 1 MX Record which points to an A Record which they points to an IP Address. Is that the IP address of your Exchange Server? which I presume is NATd on a Firewall within your infrastructure?

 

James.

[local-lad-steve]

From my understanding, the MX records sits with the isp? no? there is only a single exchange server in this organisation. i guess i would need access to the the DNS of the isp to find out about the mx records, which i dont have.

 

...and emails "5" and "8" came through 2 hours later than the others.....

 

im completely lost as to what is going off here...

[psydii]

If your server is resource constrained, which in your case is quite possible since you only have 4% disk space left on an oldish server, then backpressure may be in effect.

[local-lad-steve]

Thanks! This is something that i have looked into today. so i have managed to create another 60Gb of space on the drive and nothing changed, but, i am going to restart the server in 2 hours time to see if a kick will bring the box back into life.

[local-lad-steve]

having cleared space and give the server a reboot, exchange emails came in when I sent some test messages and I thought we were at the finish line... however it stopped working again.....

 

james, details u requested earlier as follows:

 

Domain name: obbc.com.au

ip address: 203.89.201.60

mail server host name: mail.obbc.com.au

priority: 10

 

host/alias Record type ip/hostname

adsl.obbc.com.au CNAME mail.obbc.com.au

mail.obbc.com.au A 14.201.14.48

oldmail.obbc.com.au A xxx.xxx.xxx.xxx

oldremote.obbc.com.au A xxx.xxx.xxx.xxx

remote.obbc.com.au A 14.240.126.117

Financial planning, Business Leasing & Asset Purchase, Auditing, Business Loans, O A 203.89.201.60

 

if I do a remote connectivity test analyser, sometimes it connects and sometimes it fails.

 

any more thoughts folks?

[EduTech]

The only thing that I wonder, is that your Reverse DNS Lookup points to 14-201-14-48.static.tpgi.com.au as oppose to mail.obbc.com.au

 

I have a feeling that it is DNS Related to be honest, and that is what is causing the delay on your email delivery. I have also noticed that sometimes it mail.obbc.com.au will also resolve to remote.obbc.com.au which is a different IP completely.

 

In that list their, I do not see an MX Record?

 

James.

[local-lad-steve]

having spent two days trying to clear up the exchange box, I was thinking the same and that I was looking in the wrong place. from the email I received today, the above list fell under the mx records for the domain. that's all I was provided with. With regards the remote/mail.obbc.com.au...there are event viewer errors for this, but its just for sending mail I think and outbound mail is fine. I reckon it is a DNS issue....so do you think we need to be contacting the service provider?

[RobD]

Sorry I may not be much help but is the issue only related to incoming mail i.e. is external mail working without issue?

 

Looking at https://www.wormly.com/test_smtp_server the MX record looks ok as mail.obbc.com.au connects and trys to send a mail.

 

Also have you run the exchange mail flow troubleshooter?

[local-lad-steve]

I just ran the same test and got a fail. its very temperamental:

 

Resolving hostname...

Connecting...

SMTP -> FROM SERVER:

220 remote.obbc.com.au Microsoft ESMTP MAIL Service ready at Wed, 11 Sep 2013 06:41:01 +1000

SMTP -> FROM SERVER:

250-remote.obbc.com.au Hello [184.72.226.23]

250-SIZE 52428800

250-PIPELINING

250-DSN

250-ENHANCEDSTATUSCODES

250-AUTH

250-8BITMIME

250 XXXXXXXX

MAIL FROM: [email protected]

SMTP -> FROM SERVER:

250 2.1.0 Sender OK

RCPT TO: [email protected]

SMTP -> FROM SERVER:

250 2.1.5 Recipient OK

Sending Mail Message Body...

SMTP -> FROM SERVER:

SMTP -> ERROR: DATA command not accepted from server:

Message sending failed.

 

 

Yes outbaound mail is working fine, its just inbound mail.

 

have ran all the mail flow toolbox tools, and theres no issues being thrown up.

[local-lad-steve]

having said that, ran the mail flow ttroubleshooter and it came up with the following:

 

Error submitting mail:

Mail submission failed: Error message: Server does not support secure connections..

 

im wondering if the TLS authenication for the server being enabled is causing an issue?? is it something that i can just disable or will i dig a deeper hole for myself?

[RobD]

TLS authentication where?? You need to check your receive connectors, try turning up the logging on your default connector to Verbose and have a look through the logs:

 

Receive connector protocol log files for the Transport service on Mailbox servers %ExchangeInstallPath%TransportRoles\Logs\Hub\ProtocolLog\SmtpReceive

Receive connector protocol log files for the Mailbox Transport service on Mailbox servers %ExchangeInstallPath%TransportRoles\Logs\Mailbox\ProtocolLog\SmtpReceive

Receive connector protocol log files for the Front End Transport service on Client Access servers %ExchangeInstallPath%TransportRoles\Logs\FrontEnd\ProtocolLog\SmtpReceive

 

Also how do you do spam protection?? Do you use a edge server as maybe that's blocking mail?

[sukh]

Always the same domain you're sending to?

[local-lad-steve]

When i mentioned TLS authentication i was looking at the receive connector properties, Authentication tab. i have set the receive connector to verbose for logging. it is a SBS single exchange server environment, no edge server, running windows sbs 2008. mail scanning is completely disabled right now while there are problems, and the client is getting very grump about the delay of this....so as always any suggestions are appreciated.

[local-lad-steve]

Sukh, it is inbound mail thats affected only....

[local-lad-steve]

Recreated the internet receive connector, all mail seems to be flowing as per normal now. thanks for your suggestions and help everyone.

[sukh]

Strange that creating the connector solved the issue, those are normally fine, either they work or not, sounds like yours was intermittent (Haven't read all your post). Post back if all goes wrongs again.

[RobD]

Glad you sorted it.