Send report to multiple email recipents (different smtp)

I am unable to send a report to multiple email ids (different smtp) . For example:

Email Ids : pranay_prasun@abc.com

                  pranay_prasun@xyz.com

And its working fine if i send a report to the above email ids separtely .I am facing below issue whenever i add both the email ids in the recipent list or multple emails of xyz domain.

address error. [Error sending address(es) to SMTP server. Return code: [SMTP 501

- Syntax error in parameters or arguments.].

crystalenterprise.smtp (501)

Below things already i checked :

• Already tried with semicolon and space but failed.
• Checked the destination (adaptive job server) in CMC and its configured for abc domain.

Kindly provide your feedback on this.

Regards,

Pranay