I am getting hammered by the following entries in my logs:

Apr 15 08:14:09 mail postfix/smtp[27060]: CA127721A5E: to=<info@cool-body.ru>, relay=127.0.0.1[127.0.0.1]:10026, delay=8, delays=7.3/0/0.02/0.62, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10030): 250 2.0.0 Ok: queued as 62DA0721595)
Apr 15 08:14:09 mail postfix/smtp[27060]: CA127721A5E: to=<info@elremo.ru>, relay=127.0.0.1[127.0.0.1]:10026, delay=8, delays=7.3/0/0.02/0.62, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10030): 250 2.0.0 Ok: queued as 62DA0721595)
Apr 15 08:14:09 mail postfix/smtp[27060]: CA127721A5E: to=<info@girlsigry.ru>, relay=127.0.0.1[127.0.0.1]:10026, delay=8, delays=7.3/0/0.02/0.62, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10030): 250 2.0.0 Ok: queued as 62DA0721595)
Apr 15 08:14:09 mail postfix/smtp[27060]: CA127721A5E: to=<tatiana@livebooks.ru>, relay=127.0.0.1[127.0.0.1]:10026, delay=8, delays=7.3/0/0.02/0.62, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10030): 250 2.0.0 Ok: queued as 62DA0721595)
Apr 15 08:14:09 mail postfix/smtp[27060]: CA127721A5E: to=<info@npgen.ru>, relay=127.0.0.1[127.0.0.1]:10026, delay=8, delays=7.3/0/0.02/0.62, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10030): 250 2.0.0 Ok: queued as 62DA0721595)
Apr 15 08:14:09 mail postfix/smtp[27060]: CA127721A5E: to=<info@oknoliya.ru>, relay=127.0.0.1[127.0.0.1]:10026, delay=8, delays=7.3/0/0.02/0.62, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10030): 250 2.0.0 Ok: queued as 62DA0721595)
Apr 15 08:14:09 mail postfix/smtp[27060]: CA127721A5E: to=<fc@rosbi.ru>, relay=127.0.0.1[127.0.0.1]:10026, delay=8, delays=7.3/0/0.02/0.62, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10030): 250 2.0.0 Ok: queued as 62DA0721595)
Apr 15 08:14:09 mail postfix/smtp[27060]: CA127721A5E: to=<info@servitio.ru>, relay=127.0.0.1[127.0.0.1]:10026, delay=8, delays=7.3/0/0.02/0.62, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10030): 250 2.0.0 Ok: queued as 62DA0721595)
Apr 15 08:14:09 mail postfix/smtp[27060]: CA127721A5E: to=<office@shadowww.ru>, relay=127.0.0.1[127.0.0.1]:10026, delay=8, delays=7.3/0/0.02/0.62, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10030): 250 2.0.0 Ok: queued as 62DA0721595)
Apr 15 08:14:09 mail postfix/smtp[27060]: CA127721A5E: to=<sergei.tarasov@sun.com>, relay=127.0.0.1[127.0.0.1]:10026, delay=8, delays=7.3/0/0.02/0.62, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10030): 250 2.0.0 Ok: queued as 62DA0721595)


How are these guys ale to relay off my servers? Is this possibly coming from an authorized user who has some malware?