[Last Call] Learn how to a build a cloud-first strategyRegister Now

x
?
Solved

SMTP communication problem with the recipient's email server

Posted on 2009-04-21
19
Medium Priority
?
794 Views
Last Modified: 2013-11-30
Our small business server has just started throwing up some errors. Emails are being rejected :-/. The responses say:

Subject:        Undeliverable: Our replacement bollard

Your message did not reach some or all of the intended recipients.

      Subject:  Our replacement bollard
      Sent:     21/04/2009 16:45

The following recipient(s) could not be reached:

      joanne.mannion@atgaccess.com on 21/04/2009 16:46
            There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.

            <our_mail_domain.org.uk #5.5.0 smtp;503 This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server.>

Any reason why this would have started? It has done it to two emails so far:

- atgaccess.com
- ncsmanagement.com

Any help would be appreciated!

0
Comment
Question by:OblivionSY
18 Comments
 
LVL 3

Author Comment

by:OblivionSY
ID: 24202295
There are other domains that it can't send to:

ntlworld.com (an ISP)  so it doesn't sound like it is just the odd domain having an issue. Have upped the points as this is now quite urgent!

Thanks
0
 
LVL 15

Expert Comment

by:tntmax
ID: 24203796
Do you have a reverse dns setup on your public ip? have you made any infrastructure or configuration changes to the server? Can you check if you are blacklisted at mail-abuse.org?
0
 
LVL 4

Expert Comment

by:The_Dark1
ID: 24203853
http://mxtoolbox.com/blacklists.aspx is a good site to check alos if you are blacklisted

But it sounds like your problem is local to your exchange server... are you using smart host's? OR DNS to route your mail? and as tntmax suggested is reverse DNS setup on your IP (generally handled by your iSP)
0
Problems using Powershell and Active Directory?

Managing Active Directory does not always have to be complicated.  If you are spending more time trying instead of doing, then it's time to look at something else. For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why

 
LVL 17

Expert Comment

by:Suraj
ID: 24212378
atgaccess.com is the domain for which you are not able to send right...

do nslookup in command prompt
set q=mx
atgaccess.com

what do u get??
you should get the MX..of that domain...
do telnet IP/MX 25
does it connect ? does it give u a banner?

-x

0
 
LVL 3

Author Comment

by:OblivionSY
ID: 24213394
tntmax - there is no reverse dns lookup currently.

Our domain is romfordbaptist.org.uk which the reverse lookup just goes back to tiscali.

It seems to be listed on a few, but it seems all ability to send external email suddenly dropped out.

There have not been any changes to the server, except for windows updates (may well be the cause!)

We were not using smart hosts, but I did try adding one in, though I could not enter a username and password for it, so that probably hasn't helped.

Another thing that might confused matters, is our website http://romfordbaptist.org.uk is hosted on an external server, on a different IP. Our email is hosted on our own exchange server. So the nslookup for mail.romfordbaptist.org.uk is different from just romfordbaptist.org.uk

I should point out that we're receiving email OK, and can access the web etc fine, it is purely the sending of emails.

Looking at the nslookup stuff, did the nslookup stuff as requested:

Default Server: rbc1.rbc.local
Address: 192.168.16.2

> set q=mx
> atgaccess.com
Server: rbc1.rbc.local
Address: 192.168.16.2

DNS request timed out.
      timeout was 2 seconds.
*** Request to rbc1.rbc.local timed-out

(this was run on the server rbc1)

as for the telnet - obv did not get an IP, but using the name:

C:\Documents and Settings\Administrator>telnet atgaccess.com/MX 25
Connecting To atgaccess.com/MX...Could not open connection to the host, on port
25: Connect failed

however telnet atgaccess.com 25 does work and i get 220 SMTP Server Ready

Thanks for the replies guys, please let me know if I can provide further information!

0
 
LVL 17

Expert Comment

by:Suraj
ID: 24213428
ok here this can be a dns issue or the remote domain could have blocked you...
lets clear it..

is nslookup
set q=mx
gmail.com or yahoo.com -> any this working for any external domains?? aer you getting the mx of them?? or just that domain???

do telnet 194.116.198.83 25
does this connect?? whts the response.

-x
0
 
LVL 3

Author Comment

by:OblivionSY
ID: 24215978
I did not get a response from any of them: I did each twice (the first time had a different message)

C:\Documents and Settings\Administrator>nslookup
Default Server:  rbc1.rbc.local
Address:  192.168.16.2

> set q=mx
> gmail.com
Server:  rbc1.rbc.local
Address:  192.168.16.2

*** rbc1.rbc.local can't find gmail.com: Server failed
> yahoo.com
Server:  rbc1.rbc.local
Address:  192.168.16.2

DNS request timed out.
    timeout was 2 seconds.
*** Request to rbc1.rbc.local timed-out
> gmail.com
Server:  rbc1.rbc.local
Address:  192.168.16.2

DNS request timed out.
    timeout was 2 seconds.
*** Request to rbc1.rbc.local timed-out
> yahoo.com
Server:  rbc1.rbc.local
Address:  192.168.16.2

DNS request timed out.
    timeout was 2 seconds.
*** Request to rbc1.rbc.local timed-out

The telnet was successful
220 ixe-mta-18.emailfiltering.com emfmtad 44


Would this potential issue have caused the authentication error i was getting? -

 joanne.mannion@atgaccess.com on 21/04/2009 16:46
            There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.

            <romfordbaptist.org.uk #5.5.0 smtp;503 This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server.>


0
 
LVL 17

Assisted Solution

by:Suraj
Suraj earned 800 total points
ID: 24215997
Ok so you have issue with DNS.
now try this
nslookup
set q=mx
server 4.2.2.2
yahoo.com or gmail.com

please respond fast.
0
 
LVL 17

Expert Comment

by:Suraj
ID: 24216019
I think this is your firewall issue.
telnet should work for all the domains on port 25.
This could also be a reason why your dns is not working...
check your firewall rules or settings....

-x
0
 
LVL 3

Author Comment

by:OblivionSY
ID: 24216297
the nslookup results are:

> set q=mx
> server 4.2.2.2
Default Server:  vnsc-bak.sys.gtei.net
Address:  4.2.2.2

> yahoo.com
Server:  vnsc-bak.sys.gtei.net
Address:  4.2.2.2

DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
*** Request to vnsc-bak.sys.gtei.net timed-out
> gmail.com
Server:  vnsc-bak.sys.gtei.net
Address:  4.2.2.2

DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
*** Request to vnsc-bak.sys.gtei.net timed-out

Checking Firewall now
0
 
LVL 3

Author Comment

by:OblivionSY
ID: 24216333
There is no firewall actually running on the server :-/

The windows one says: "Windows Firewall cannot run because another program or service is running that might use the network address translation component (Ipnat.sys).

Router only has an inbound firewall running. Any thoughts?

Am i suppose to see more than what I did for the telnet commands? Any way of seeing where it is blocked?
0
 
LVL 17

Expert Comment

by:Suraj
ID: 24216386
Firewall on the network is what i meant to say..
may on the router or physical one...
do one more thing

do teh same nslookup thing and also that 4.2.2.2 thing on the DNS SERVER itself and see if you are getting any MX?

if not... buddy its something on the network which is causing the issue....

-x
0
 
LVL 3

Author Comment

by:OblivionSY
ID: 24216733
I'm confused as we can access any webpage, so the DNS is working for those? Also, I can connect via telnet to the IP and port 25.

Since it is a Small Business Server, the DNS and Exchange are all on the same box.
0
 
LVL 3

Accepted Solution

by:
OblivionSY earned 0 total points
ID: 24232000
Ok I have found out what the issue was. In the DNS, there was a forward lookup to the router, and then two primary and secondary DNS of our ISP. I removed the router IP and it all started working again. It seems the DNS is set to time out and move on after 5 seconds, any reason why it didn't move on to the next DNS entry?

Thankfully the emails are all being sent again. Thanks for the diagnosis help x-sam
0
 
LVL 17

Expert Comment

by:Suraj
ID: 24234963
You are closing this without granting points? Though i helped you? Not fair
0
 
LVL 17

Expert Comment

by:Suraj
ID: 24237175
modus_in_rebus
I had helped the Asked to resolve the issue. Is it wise to just close the case though i helped to resolve the question. Just wanted to know the reason. Please check the answers again and do the needfull.
After checking the answers, whatever desicion you take.. its fine with me.No problem
Thanks
x-sam
0
 
LVL 3

Author Comment

by:OblivionSY
ID: 24239760
I did assign points.... You were helpful, and should have some points... let me see what happened :-/
0
 
LVL 3

Author Comment

by:OblivionSY
ID: 24239777
Glad it was all sorted on http://www.experts-exchange.com/Community_Support/General/Q_24355919.html

Thanks guys, another great service :-)
0

Featured Post

Restore individual SQL databases with ease

Veeam Explorer for Microsoft SQL Server delivers an easy-to-use, wizard-driven interface for restoring your databases from a backup. No expert SQL background required. Web interface provides a complete view of all available SQL databases to simplify the recovery of lost database

Question has a verified solution.

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

There can be many situations demanding the conversion of Outlook OST files to PST format and as such, there is no shortage of automated tools to perform this conversion. However, what makes Stellar OST to PST converter stand above the rest? Let us e…
Exchange administrators are always vigilant about Exchange crashes and disasters that are possible any time. It is quite essential to identify the symptoms of a possible Exchange issue and be prepared with a proper recovery plan. There are multiple…
This video discusses moving either the default database or any database to a new volume.
This video shows how to quickly and easily add an email signature for all users on Exchange 2016. The resulting signature is applied on a server level by Exchange Online. The email signature template has been downloaded from: www.mail-signatures…
Suggested Courses
Course of the Month18 days, 5 hours left to enroll

829 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