You will be lucky to get a response to an email. Most companies instruct their employees to ignore emails.
I have a proof print of a Cumbrian inn ( now a posh hotel) by a recognised artist, which I have tried to sell to them by sending emails. No response. I rang the hotel and spoke to the manager. He said he had corporate instructions to say nothing and do nothing if faced by this situation. Emails and telephone contact to be ignored.
I still have a couple of ideas, but it convinces me that the best approach is to actually target the right individual within an organisation, send a Snail Mail, and then mark the envelope "Personal, Confidential". If you want the extra assurance. send it Recorded - cheap, and they have to sign. Make sure the man is actually still with the company.
Yeh, right, I've had trouble talking to a couple of my millionaire relatives with "dragons on the desk" for secretaries. Practice gets you through, if you are not talking BS.
You want to make an offer? Send it SnailMail, send it by the cheapest "signed-for" service. I'll write you a letter for £10 ... send me a PM. Pardon my cynicism, but I am fed up of donating my skills for nowt.