[CentOS] what process is sending this packet?

Mon Dec 27 14:30:03 UTC 2010
S Mathias <smathias1972 at yahoo.com>

I can see, that theres a program that keeps sending packets on port 25:

Dec 27 14:11:46 a kernel: [ 6336.992320] O_D_LOG: IN= OUT=lo SRC=127.0.0.1 DST=127.0.0.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=61533 DF PROTO=TCP SPT=37263 DPT=25 WINDOW=32792 RES=0x00 SYN URGP=0 
Dec 27 14:12:01 a kernel: [ 6352.635704] O_D_LOG: IN= OUT=lo SRC=127.0.0.1 DST=127.0.0.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=55853 DF PROTO=TCP SPT=40644 DPT=25 WINDOW=32792 RES=0x00 SYN URGP=0 
Dec 27 14:12:04 a kernel: [ 6355.641085] O_D_LOG: IN= OUT=lo SRC=127.0.0.1 DST=127.0.0.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=55854 DF PROTO=TCP SPT=40644 DPT=25 WINDOW=32792 RES=0x00 SYN URGP=0 
Dec 27 14:12:10 a kernel: [ 6361.649059] O_D_LOG: IN= OUT=lo SRC=127.0.0.1 DST=127.0.0.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=55855 DF PROTO=TCP SPT=40644 DPT=25 WINDOW=32792 RES=0x00 SYN URGP=0 

but where or how could i find out, that what process sends these packets?

thank you!