why my emails go to junk mail :(

[eluser]Sumon[/eluser]
well, i find out a good difference in header for inbox and spam yahoo mail. here is the good header

Code:

Authentication-Results:         mta144.mail.ac4.yahoo.com from=other-server.com; domainkeys=neutral (no sig); from=other-servr.com; dkim=neutral (no sig)

and here goes spam one

Code:

incorrect: Authentication-Results:         mta179.mail.ac4.yahoo.com from=shopno-dinga.com; domainkeys=pass (ok); from=shopno-dinga.com; dkim=neutral (no sig)

domainkeys are different here. is it completely server issue or we can do control domainkeys using CI.