e-mail address of UK businesses

We are looking for the e-mail addresses of between 30,000 and 40,000 businesses in the UK. We will provide the list of business names, addresses, and postcodes. Please detail in your bid which skill you will use (e.g. web searching, web scraping etc) and the method. Please also detail the estimate of the amount of time you expect it to take. Any bids which do not mention this will be disregarded.