• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 297
  • Last Modified:

URGENT: Exchange blocking outgoing emails !

This is a bit of a long winded question but i'll simplify it as much as possibe.

The problem is that all of a sudden our webserver has stopped sending (CDO generated) outgoing emails and if you look at the queue it says that "Unable to Bind to the DNS server".
See this image:
This happens for ALL of the outgoing items in the queue.

More information:
Our webserver was prevously used as a POP3 accessed exchange server.  Since then we have left exchange server on the machine as it seems to give greater control over SMTP.  
We have SMTP locked down so that only the machine ITSELF can use it (as we had issues with an open relay before).  
This configuration has worked for over a year now.  
No configurations have been changed recently.  
DNS stuff is working on that machine... (if i open internet explorer and type a site name it will resolve that address)
No code has been changed for the ASP pages using CDO to send emails.
I have tried restarting exchange.
I have tried restarting SMTP service.
I have tried restarting IIS.
All of the above refresh the queue, but it still ends up at the same situation.

Please help ASAP.
1 Solution
David WilhoitSenior Consultant, ExchangeCommented:
The only thing I can think of is that SMTP is broken. Did you re-apply a service pack for windows, or change the IIS config? check out these articles, if this doesn't work, post event log errors.



telnet to port 25 on your mail server, make sure that you see the Exchange specific commands listed when you do the EHLO command.

coopaAuthor Commented:
okay, cheers for posting so quickly.
First article, read and tried that.  Have placed that key in registry and resarted service.  I then removed it.  Nothing. Doesn't work.

Second article "Cannot Send Mail After Re-Installing the IIS SMTP Service"   I have not re-installed the SMTP service so prolly not relevant.

The additional command verbs for the Exchange 2000 SMTP service WERE present.

Anything else i can try?

Can i revert back to the IIS SMTP gateway ?

Thanks again.
David WilhoitSenior Consultant, ExchangeCommented:
what do you mean, "revert"?

BTW, that article stated to reinstall exchange, did you? 279616

you'd also have to reapply the Exchange service pack.

Free tool for managing users' photos in Office 365

Easily upload multiple users’ photos to Office 365. Manage them with an intuitive GUI and use handy built-in cropping and resizing options. Link photos with users based on Azure AD attributes. Free tool!

coopaAuthor Commented:
> what do you mean, "revert"?
When you install IIS it comes with it's own SMTP gateway... it's simple but WORKS...  8o)  
Exchange replaces this with it's own "enhanced" version.

> BTW, that article stated to reinstall exchange, did you?
No... Looking for a quicker fix... but to be honest exchange isn't being used on that system anyway... so UNinstalling it might be a better idea.  I just want to know what SMTP gateway that will leave me with.

Will attempt a system restart after lunch.

I admit, I am looking for a quick fix, but this system hosts over 20 sites almost all of which have inpage email facilities... so I'm looking to move the SMTP off and on to a linux box, which i can get working in no time, but that still leaves all of the thousands of emails that are waiting to go out from the existing SMTP.

David WilhoitSenior Consultant, ExchangeCommented:
It didn't say to uninstall, just reinstall. the truth is, something DID change, or else it would still be working. this looks like it's the SMTP or a metabase problem, IIS. Reinstalling and applying the SP could work. Is there a firewall in front of you that changed? Is there a front-end server? something? I did some further digging, and this really is a problem with SMTP and the IIS, so unless you want to try reinstalling, you'll need to wait on someone else....or if it's company critical, call the MS support team, see if they can clear it up.

gotta run out the door, time to go to work, I'll check back in later.

coopaAuthor Commented:

We changed ISPs about 8 months ago/

The SMTP server was still looking at our old ISP DNS servers... I assumed it would use the ones specified in the network settings... but no...

Found it in an ADVANCED settings menu.

Thanks for your help Kidego.
David WilhoitSenior Consultant, ExchangeCommented:
It was all you, congrats!

No comment has been added to this question in more than 21 days, so it is now classified as abandoned.

I will leave the following recommendation for this question in the Cleanup topic area:
   PAQ/ Refund

Any objections should be posted here in the next 4 days. After that time, the question will be closed.

EE Cleanup Volunteer
PAQed, with points refunded (300)

ee_ai_construct - (re-order part number #xm34)
Community Support Moderator

Featured Post

Easily manage email signatures in Office 365

Managing email signatures in Office 365 can be a challenging task if you don't have the right tool. CodeTwo Email Signatures for Office 365 will help you implement a unified email signature look, no matter what email client is used by users. Test it for free!

Tackle projects and never again get stuck behind a technical roadblock.
Join Now