Emails going to junk folder

Hi,

Im seeing an increase of emails that are send by our users to other organizations going to junk folder.

I did go through regular verification if we are blacklisted and other things that might decrease our score on remote email security appliance but I cant really find anything. We do have rDNS record and SPF record set up. There is no bulk emailing.

Is there a way for me to increase the score so emails wont wind up in junk folder at other organizations.