Use customer contacts to help determine safe senders

We have a client who is a finance company who has an enormous amount of contacts in their Outlook that email them on a regular basis. When we switched to INKY, a great many of those emails got marked as Graymail or SPAM, even though they communicate with them regularly and we got some very loud complaints about it. INKY should be able to access those contacts lists based on the permissions that it has. Could INKY use these contacts to help properly weight these incoming emails to reduce the number of false positives in the system or in Graymail? Manually adding all of these to Known External for this client (or all clients) is a large amount of work.