we have exchange setup and all is working owa and inside mail is working. inside imap is working. outside imap can receive email but cannot send.

check if the ports are blocked on your internet facing firewall

Hi,

IMAP is a mail retrieval mechanism, it is not used for sending email. This is where the SMTP (Simple Mail Transfer Protocol) comes in to play.

You need to ensure that there is a Receive Connector set up in Exchange 2010 for client connectivity, and the port is opened in your firewall to allow SMTP through to the Receive Connector.

Hi,

I agree with Cameron.

Please make sure that there is an SMTP Connector set up in Exchange 2010.

POP3 and IMAP4 cant be used to send messages from a client application to the e-mail server. E-mail applications that use POP3 and IMAP4 to send messages rely on the SMTP protocol to send messages.

Following is the article about Understand POP3 and IMAP4:

http://technet.microsoft.com/en-us/library/bb124107(v=exchg.141).aspx#SendReceive

 

I would also suggest you to provide the correct port number for the SMTP connection to working properly.

If you do not know the port number, I would suggest you to check with the E-mail service provider.

 

Hope it is helpful

If you are satisfied with my solution, please mark as an answer.

 

Thanks

Mavis