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.

On Tue, 29 May 2012 10:41:25 +0000, AmitAggarwal wrote: >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. If you're using a 3rd-party system to send e-mail you probably don't have direct access to the Internet on port 25. Without that there's no way to verify the existence of an e-mail address. Even if you do have such access you can't verify the existence of an address with certainty. You may send a RCPT TO and the receiving system may reply "250" even if the recipient doesn't exist. --- Rich Matheisen MCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP

On Tue, 29 May 2012 10:41:25 +0000, AmitAggarwal wrote: >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. If you're using a 3rd-party system to send e-mail you probably don't have direct access to the Internet on port 25. Without that there's no way to verify the existence of an e-mail address. Even if you do have such access you can't verify the existence of an address with certainty. You may send a RCPT TO and the receiving system may reply "250" even if the recipient doesn't exist. --- Rich Matheisen MCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP

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.

On Wed, 30 May 2012 06:53:27 +0000, AmitAggarwal wrote: >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. Why would any of your servers generate a NDR for a message that the reciving domain accepted without complaint??? >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. Okay, so how do you expect to know if an address exists or not if the responsible e-mail systems won't tell you? >Now the sender and receipient wants to know where they can find the email and why the NDR was not generated. You say you have a DSN (i.e. a confirmation) from the receiving domain that they accepted the message and accept responsibiity for delivery? Now it's up to them to determine where the message went, not you. --- Rich Matheisen MCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP

On Wed, 30 May 2012 06:53:27 +0000, AmitAggarwal wrote: >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. Why would any of your servers generate a NDR for a message that the reciving domain accepted without complaint??? >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. Okay, so how do you expect to know if an address exists or not if the responsible e-mail systems won't tell you? >Now the sender and receipient wants to know where they can find the email and why the NDR was not generated. You say you have a DSN (i.e. a confirmation) from the receiving domain that they accepted the message and accept responsibiity for delivery? Now it's up to them to determine where the message went, not you. --- Rich Matheisen MCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP