Sure, makes sense. Have you thought about just trying a relationship and using summary fields? If you're able to match the email to the PO, instead of incrementing / updating the fields, you could consider just having the Pipeline fill out the 'Related PO' and then use the native summary fields to summarize the # or orders, qty or whatever, and then also use the summary combined text as well for text values.
The pipeline will work but using the relationship will help backfill for older emails/POs and be a little more error proof since the relationship can be adapted/changed on the fly instead of using scalar data.
I didn't realize I could concatenate text with a summary field. I will look into that. No to back fill records at this point but still good to consider the relationship approach.
Yep - there is a combined text summary field that allows you to summarize text fields from your child table - works great for a situation like you've outlined.
