Summary of three different sheets with one common column - and then email out

Hi there

This is my first time on an excel forum so please bear with me..
I need to create a summery sheet of the results (average scores) of 3 spreadsheets - all different except the supplier column. I then need to email these results out.

Someone has manually populated a results template already from one spreadsheet - however there are over 300 suppliers and several results for each one thus making this an extremely long task! They have also created a separate tab for each supplier which personally I think could be unnecessary?

I also wish to then send the results summary for each supplier by email to them with the results averaged for them.

Is this even possible???
Id be grateful for any help at all