I finally solved... I deleted the entry end set it again... I just did copy&paste but now it works...
...right, i also just did copy then made a little changes as follow:
root@squidserver:/home/superuser# vim /etc/bind/zones/ptpn4.co.id.db
ptpn4.co.id. 3600 IN TXT "v=spf1 mx mx:iredmail.ptpn4.co.id -all"
; key#1, domain ptpn4.co.id, /var/lib/dkim/ptpn4.co.id.pem
dkim._domainkey.ptpn4.co.id. 3600 TXT "v=DKIM1; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDW37GR1sdUNLS6ydploT4LZwumpilEobAMp30qFza9Ex... "
root@squidserver:/home/superuser# amavisd-new testkeys
TESTING#1: dkim._domainkey.ptpn4.co.id => pass
root@squidserver:/home/superuser# dig -t txt dkim._domainkey.ptpn4.co.id
; <<>> DiG 9.8.1-P1 <<>> -t txt dkim._domainkey.ptpn4.co.id
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50243
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1
;; QUESTION SECTION:
;dkim._domainkey.ptpn4.co.id. IN TXT
;; ANSWER SECTION:
dkim._domainkey.ptpn4.co.id. 3600 IN TXT "v=DKIM1\; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDW37GR1sdUNLS6ydploT4LZwumpilEobAMp+30qFza9ExGGPaqxsy6maYdrp86gmuOybKzMTHQGHJvaXDMLwoD/hIVW6m3g9Z2tSnYD4ajGHDbtqhUBqi6FcnvJlJrWXU8HvLq+aC39sFwjyCiGm+ZT9hPfk4cyu10PfnCIEFLMwIDAQAB"
;; AUTHORITY SECTION:
ptpn4.co.id. 3600 IN NS dns.ptpn4.co.id.
;; ADDITIONAL SECTION:
dns.ptpn4.co.id. 3600 IN A 10.10.5.200
;; Query time: 0 msec
;; SERVER: 10.10.5.200#53(10.10.5.200)
;; WHEN: Tue Aug 13 17:17:13 2013
;; MSG SIZE rcvd: 319