Large number of push notifications

My network administrator found out that my Mac is sending enormous amounts of push notifications.:

14:54:57.045340 IP 172.19.134.229.50256 > nk11p01st-courier037-bz.push.apple.com.5223: Flags [S], seq 1259093567, win 65535, options [mss 1460,nop,wscale 1,nop,nop,TS val 268727709 ecr 0,sackOK,eol], length 0

14:54:57.550043 IP 172.19.134.229.50250 > nk11p01st-courier034-bz.push.apple.com.5223: Flags [S], seq 2417046899, win 65535, options [mss 1460,nop,wscale 1,nop,nop,TS val 268728211 ecr 0,sackOK,eol], length 0

14:54:57.550161 IP 172.19.134.229.50249 > nk11p01st-courier133-bz.push.apple.com.5223: Flags [S], seq 1032570061, win 65535, options [mss 1460,nop,wscale 1,nop,nop,TS val 268728211 ecr 0,sackOK,eol], length 0

14:54:57.650486 IP 172.19.134.229.50252 > nk11p01st-courier149-bz.push.apple.com.5223: Flags [S], seq 3772464618, win 65535, options [mss 1460,nop,wscale 1,nop,nop,TS val 268728311 ecr 0,sackOK,eol], length 0

14:54:57.650585 IP 172.19.134.229.50251 > nk11p01st-courier120-bz.push.apple.com.5223: Flags [S], seq 907277027, win 65535, options [mss 1460,nop,wscale 1,nop,nop,TS val 268728311 ecr 0,sackOK,eol], length 0

14:54:57.751059 IP 172.19.134.229.50254 > nk11p01st-courier088-bz.push.apple.com.5223: Flags [S], seq 459004747, win 65535, options [mss 1460,nop,wscale 1,nop,nop,TS val 268728410 ecr 0,sackOK,eol], length 0

14:54:57.751348 IP 172.19.134.229.50253 > nk11p01st-hpaj392840-bz.push.apple.com.5223: Flags [S], seq 2989148224, win 65535, options [mss 1460,nop,wscale 1,nop,nop,TS val 268728410 ecr 0,sackOK,eol], length 0

14:54:57.852133 IP 172.19.134.229.50255 > nk11p01st-courier098-bz.push.apple.com.5223: Flags [S], seq 301788667, win 65535, options [mss 1460,nop,wscale 1,nop,nop,TS val 268728511 ecr 0,sackOK,eol], length 0

So that it about 8 per second, or almost 30,000 per hour.

So I was wondering if anyone knows how to stop this. It's a problem on port 5223, so it must be from one of these software: iCloud DAV Services (Contacts, Calenders, Bookmarks), APNS, Facetime, Game Centre, Photo stream, Back to my mac.

However, I have already turned off the iCloud services, and I am not using Facetime or Game Centre.

Also, I have already tried the advice on this blog (http://support.apple.com/kb/HT3789#), but that didn't work either.

Thanks.