This is the mail system at host
smtp4.fastdnsnetwork.com.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to <postmaster>
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
<sbi4833(a)cal3.vsnl.net.in>: host mta3.vsnl.net[203.200.235.143] said: 550 5.1.1
unknown or illegal alias: sbi4833(a)cal3.vsnl.net.in (in reply to RCPT TO
command)