Issue with Lookup Value from Gmail to Airtable Integration

First question: After a Gmail Email received trigger I am querying Airtable via "Find many records" using a Lookup Value of the From address. I try to pick this up from the Gmail email.from parameter but this seems to default to the received (agent) email address. I've tried email.to but always get the agent address. If I hard code the address I then get records returned but this won't work in production of course. Any ideas? Mark