I don't believe that will make a difference.
What it looks like is happening is that your inbound mailer is doing verification based on the absolute sender rather than the envelope sender, and trying to determine if
postmaster@colo50.mia.colo-cation.com is a valid address (which it isn't).
I would suspect the same issue on link-o-rama.com since they also send mail from natxxx.national-net.com -- which doesn't accept mail -- and all mail is filtered through a central MX.
Once you turn off that spam verification, you'll probably have no problem accepting mail from either of those.
In the meantime, I've made a note on our side to deal with this situation as I've not seen many places do RFC validation on inbound email.