In your company if you are looking to setup a rule or a policy on receiving gifts, we have a suggestion, Share the Fun!
Its fairly simple, setup a corporate gifting policy and share it with all your vendors that suits your office.
Allow vendors to give gifts that could be used by the entire office (not just the purchasing department). Not only did this raise morale and support vendors who insist on sending gifts, it eliminated much of the office resentment from junior level employees who were often left out. With a large office, this can be difficult, though you would be surprised how far a chocolate basket will go.
Happy Corporate Gifting!