Formula to find match and then pull out corresponding data

I couldn't think of a good title but this is what I am looking to do.

I have a master spreadsheet with 5,000 Columns. Each column has a company name in Row A and email address in Row B.

In another spreadsheet I have a subset of 250 company names (which are listed somewhere in the master spreadsheet) but no email address.

Is there a formula such as a FIND formula or something that will search column A for the match and then will paste in the corresponding email address? basically the formula would say find the match to this and then paste the cell next to the match?

I am pretty sure this is a simple formula, but not exactly sure how to do it.

Thanks in advance.