To figure out which package a particular file belongs to, use the following:

server> pkgchk -l -p /absolute/path/todir


For example:
server> pkgchk -l -p /usr/dt/bin/netscape
Pathname: /usr/dt/bin/netscape
Type: symbolic link
Source of link: ../appconfig/netscape/netscape
Referenced by the following packages:
        NSCPcom        
Current status: installed

server> pkgchk -l -p /usr/lib/sendmail
Pathname: /usr/lib/sendmail
Type: regular file
Expected mode: 2555
Expected owner: root
Expected group: smmsp
Expected file size (bytes): 967836
Expected sum(1) of contents: 26668
Expected last modification: Apr 06 18:07:42 2002
Referenced by the following packages:
        SUNWsndmu      
Current status: installed


Or, to directly view the file yourself:

server> grep /usr/lib/sendmail /var/sadm/install/contents
/usr/lib/sendmail f none 4555 root bin 658616 55541 947116988 SUNWsndmu