You sure can.
Once a blogger has sent a proposal on your job, it opens up the opportunity to contact them via our messaging portal to discuss the campaign details if you wish to before you hire. This can be particularly useful when your campaign is complex and you want to sound out the blogger before hiring. Or useful if you want to check specific metrics or check availability with a blogger.
However, as the lines of communication are open, we do encourage you to keep the conversation within your Get Blogged accounts as we cannot protect any funds outside of the platform.