If you enable the option One row per email conversation then each Gmail email conversation will be one spreadsheet row. So if you have email conversations with emails (original email and reply) then you will see one row and the original email and reply will be merged into one PDF. Gmail email conversations are explained here.

If you enable the option One row per email message then each Gmail email message will be one spreadsheet row. So if you have email conversations with emails (original email and reply) then you will see two rows – one for the original email and one for the reply.

Here’s an example for clarification:

Say you’ve set up a single parsing rule, one that extracts invoice numbers from your emails. The parser searches for the text “Invoice #” and uses the number that comes after that text to identify the invoice’s unique number.

When the parser runs into an email message which does not have the text “Invoice #” in its body, then it will simply skip that email. Nothing from that email will show up in the spreadsheet.

automatically save emails