Dkim not signing with mailsend.php

Hi,

Im new here, just switched from another CP, i really liked virtual min, but im stuck in some features, like giving all available resources to a newly created virtual server (if thats posssble) but the nightmare for me is that if i send an email to mailtest@unlocktheinbox.com from Mail (Mac OSX Mail Client) dkim pass but if i sent it from active campaign, e mail marketing software, dkim signature fails, in the CP im switching from it did not happens, so i want to know if someone knows what can be happening. i tried both ways letting virtualmin install dkim-filter, and manually installing opendkim, im running centos 6.3 i 686.

Thanks a lot