jpg file quarantined like program

[Jorge Arenas]

Hi:

I hope someone can help me, MailScanner is stopping jpg files because 
filetype found a program in the file

Logs:
May 18 08:05:40  MailScanner[26740]: Filetype Checks: No executables 
(n4ID5VeT032705 166245Delfines.jpg)
May 18 08:05:40  MailScanner[26740]: Other Checks: Found 1 problems
May 18 08:05:40  MailScanner[26740]: Virus and Content Scanning: Starting
May 18 08:05:44  MailScanner[26740]: Virus Scanning completed at 161379 
bytes per second
May 18 08:05:44  MailScanner[26740]: Saved entire message to 
/var/spool/MailScanner/quarantine/20090518/n4ID5VeT032705
May 18 08:05:44  MailScanner[26740]: Saved infected "166245Delfines.jpg" to 
/var/spool/MailScanner/quarantine/20090518/n4ID5VeT032705

I believe MS uses file to determine the type so, I execute:

# file 166245Delfines.jpg
166245Delfines.jpg: JPEG image data, JFIF standard 1.01, comment: 
"<nso="delfines.nso"> "

I do not know why MS detect an Executable in this type of file

can anyone help me

thanks in advance

Jorge Arenas