Mails cant be sent from SAP ( quality server ) to lotus notes

Hii all,

I can able to send mails from production server as well from development server to lotus notes but am not able to send mails from quality server.

We are using Node SMTP using INT( Internet mail address) for all the servers and we have maintained the same parameters ifor all in transaction SCOT.

When ever we send a mail from quality server to lotus notes an error status appears in transaction SOST. when I click on that, a pop up screen appears saying that "Cannot process message, no route from sender to xyz@abc.com.

Please suggest me the problem and solution for the same ASAP.

Regards,

Ganesh Nag G.