Hello, We are running Exchange 2010 with SP2 in our network. We are using Ironport as the gateway. My query is: If I have to send an email to external email id, how can I check whether it is a valid email id before I send actualy email to this recipient. e.g. Say my domain is amit@internal.com. Now I have to send an email to say xyz@external.com. But before sending an email to this id, I need to verify whether this email id exists and is valid. Kindly suggest.

As per my knowledge it is not possible. Kottees : My Blog : Please mark it as an answer if it really helps you.

I went through the following link, but not sure if we can really use this. http://www.webdigi.co.uk/blog/2009/how-to-check-if-an-email-address-exists-without-sending-an-email/

this is also kind of sending an email to that particular external address. but this is not possible for all the external id's.Kottees : My Blog : Please mark it as an answer if it really helps you.

Let me explain our setup: We have Exchange 2010 with SP2 and use Ironport as gateway. Recently I sent an email to xyz@externaldomain.com, and the email has gone from the Exchange and Ironport both. We got deliver notification at Ironport that the email has been delivered to externaldomain. But later the client said that his email id is different abc@externaldomain.com. Our server is capable of generating NDRs. It's been more than 3 months but we haven't received any NDR till date for email sent to xyz@externaldomain.com. When we do a telnet and type this email id in rcpt to, we get recipient ok response. Now the sender and receipient wants to know where they can find the email and why the NDR was not generated.

hi, >>>Now the sender and receipient wants to know where they can find the email and why the NDR was not generated. If the remote domain has configured that not send NDR. You will not receive it. NDR is not generated by your server in this case. If the address that you sent is exist, i think the message has been delivered to his mailbox. If the address is not exist, i think the message is still in your exchange unreachable queue. You can use the tool:queue viewer to check. hope can help you thanks,CastinLu TechNet Community Support

If there was a way to know, then it would be abused by spammers. You can do tests to see how the server responds, but if the email admin has their server setup correctly, the results will either be delayed or you will get blacklisted. As per your other question, you cannot really take in to account the poor configuration of remote servers, it isn't your problem if they haven't setup the server correctly. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.