postfix mail not delivered

Say, this is the log - please help...

>, relay=root@localhost
Mar 23 22:03:51 localhost postfix/smtpd[6446]: warning: database /etc/postfix/virtual.db is older than source file /etc/postfix/virtual
Mar 23 22:03:51 localhost postfix/smtpd[6446]: connect from localhost[127.0.0.1]
Mar 23 22:03:51 localhost postfix/trivial-rewrite[6448]: warning: database /etc/postfix/virtual.db is older than source file /etc/postfix/virtual
Mar 23 22:03:51 localhost postfix/cleanup[6449]: warning: database /etc/postfix/virtual.db is older than source file /etc/postfix/virtual
Mar 23 22:03:51 localhost postfix/smtpd[6446]: 8806D2A205E7: client=localhost[127.0.0.1]
Mar 23 22:03:51 localhost postfix/cleanup[6449]: 8806D2A205E7: message-id=<201003232003.o2NK3a0E006439@localhost.a1telecoms.co.za>
Mar 23 22:03:51 localhost postfix/qmgr[6425]: 8806D2A205E7: from=<root@localhost.a1telecoms.co.za>, size=593, nrcpt=1 (queue active)
Mar 23 22:03:51 localhost sendmail[6439]: o2NK3a0E006439: to=iscafax@a1telecoms.co.za, ctladdr=root (0/0), delay=00:00:15, xdelay=00:00:00, mailer=relay, pri=30051, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (Ok: queued as 8806D2A205E7)
Mar 23 22:03:51 localhost postfix/smtpd[6446]: disconnect from localhost[127.0.0.1]
Mar 23 22:04:10 localhost postfix/smtp[6450]: 8806D2A205E7: host fw1a.a1telecoms.co.za[196.220.48.4] said: 450 4.1.8 <root@localhost.a1telecoms.co.za>: Sender address rejected: Domain not found (in reply to RCPT TO command)
Mar 23 22:04:19 localhost postfix/smtp[6450]: 8806D2A205E7: to=<a1telecoms.co.za@a1telecoms.co.za>, orig_to=<iscafax@a1telecoms.co.za>, relay=fw2a.a1telecoms.co.za[196.220.48.7]:25, delay=28, delays=0.1/0.01/26/1.7, dsn=4.1.8, status=deferred (host fw2a.a1telecoms.co.za[196.220.48.7] said: 450 4.1.8 <root@localhost.a1telecoms.co.za>: Sender address rejected: Domain not found (in reply to RCPT TO command))