Spam wychodzący z serwera - postfix

[arokus]

Witam,
mam pewien problem, mianowicie, zarządzam w tej chwili serwerem pocztowym korzystając z postfix'a i zauważyłem dziwną rzecz. Pomimo, że dziennie wysyłane jest średnio 20 maili, pliki logów pocztowych podchodzą pod 200 MB.
Zacząłem je przeglądać i zdziwiłem się po raz kolejny, bo wyglądają tak jakby mój serwer prawie non-stop wysyłał mnóstwo maili na nieznane mi adresy:

Kod: [Zaznacz]

Feb  2 07:38:53 mailhost postfix/smtp[19340]: connect to gateway.net[205.188.100.58]:25: Connection timed out
Feb  2 07:38:55 mailhost postfix/smtp[19334]: connect to imp-1.mail.tiscali.it[213.205.33.248]:25: Connection timed out
Feb  2 07:38:55 mailhost postfix/smtp[19334]: 46BBD6C50C4: to=, relay=none, delay=255133, delays=255042/0.74/90/0, dsn=4.4.1, status=deferred (connect to imp-1.mail.tiscali.it[213.205.33.248]:25: Connection timed out)
Feb  2 07:38:56 mailhost postfix/smtp[19360]: connect to mx12.unit.tiscali.de[213.205.33.187]:25: Connection timed out
Feb  2 07:38:58 mailhost postfix/smtp[19309]: connect to rronline.com[12.169.153.10]:25: Connection timed out
Feb  2 07:38:58 mailhost postfix/smtp[19309]: 8F3656C55DD: to=, relay=none, delay=246469, delays=246397/12/60/0, dsn=4.4.1, status=deferred (connect to rronline.com[12.169.153.10]:25: Connection timed out)
Feb  2 07:38:58 mailhost postfix/smtp[19304]: connect to attcanada.ca[165.160.15.20]:25: Connection timed out
Feb  2 07:38:58 mailhost postfix/smtp[19304]: 8B3DB6C527A: to=, relay=none, delay=252797, delays=252724/13/60/0, dsn=4.4.1, status=deferred (connect to attcanada.ca[165.160.15.20]:25: Connection timed out)
Feb  2 07:38:59 mailhost postfix/smtp[19336]: connect to boron.interprise.co.za[196.36.199.111]:25: Connection timed out
Feb  2 07:38:59 mailhost postfix/smtp[19330]: connect to gateway.net[64.12.79.57]:25: Connection timed out
Feb  2 07:38:59 mailhost postfix/smtp[19351]: connect to ouc.bc.ca[142.23.25.252]:25: Connection timed out
Feb  2 07:39:00 mailhost postfix/smtp[19373]: connect to gateway.net[64.12.79.57]:25: Connection timed out
Feb  2 07:39:00 mailhost postfix/smtp[19306]: connect to dalgate3.metlifehomeloans.com[208.65.44.18]:25: Connection timed out
Feb  2 07:39:00 mailhost postfix/smtp[19306]: 83F856C51E5: to=, relay=none, delay=254025, delays=253954/11/60/0, dsn=4.4.1, status=deferred (connect to dalgate3.metlifehomeloans.com[208.65.44.18]:25: Connection timed out)
Feb  2 07:39:00 mailhost postfix/smtp[19315]: connect to firstunion.com[169.200.88.112]:25: Connection timed out
Feb  2 07:39:00 mailhost postfix/smtp[19315]: 8168A6C55CE: to=, relay=none, delay=246568, delays=246495/12/60/0, dsn=4.4.1, status=deferred (connect to firstunion.com[169.200.88.112]:25: Connection timed out)
Feb  2 07:39:00 mailhost postfix/smtp[19324]: connect to gateway.net[64.12.50.151]:25: Connection timed out
Feb  2 07:39:01 mailhost postfix/smtp[19286]: connect to mxs1.saleandpartners.com[69.64.155.127]:25: Connection timed out
Feb  2 07:39:01 mailhost postfix/smtp[19286]: 7F9356C50CD: to=, relay=none, delay=254979, delays=254908/11/60/0, dsn=4.4.1, status=deferred (connect to mxs1.saleandpartners.com[69.64.155.127]:25: Connection timed out)
Feb  2 07:39:01 mailhost postfix/smtp[19458]: connect to gateway.net[64.12.79.57]:25: Connection timed out
Feb  2 07:39:01 mailhost postfix/smtp[19457]: connect to mail.sis.gov.ps[216.136.71.137]:25: Connection timed out
Feb  2 07:39:01 mailhost postfix/smtp[19457]: 7F42E6C502C: to=, relay=none, delay=255009, delays=254938/11/60/0, dsn=4.4.1, status=deferred (connect to mail.sis.gov.ps[216.136.71.137]:25: Connection timed out)
Feb  2 07:39:01 mailhost postfix/smtp[19336]: C94736C53AE: to=, relay=mail.interprise.co.za[196.3.167.50]:25, delay=250628, delays=250535/0.07/93/0.5, dsn=4.1.8, status=deferred (host mail.interprise.co.za[196.3.167.50] said: 450 4.1.8 : Sender address rejected: Domain not found (in reply to RCPT TO command))

Prawdopodobnie przez to zostałem dodany na blacklistę i nie mogę wysyłać maili na zewnątrz. Jak ugryźć ten problem i pozbyć się tej niechcianej wysyłanej poczty ?
Pozdrawiam - arokus