If you have a current Sage 300 install ( I think 2019+) with Multiple Contacts (It might be a subscription feature), it also allows you to enter multiple contacts and there is a switch to include the email when sending A/R Invoices and/or Receipts and/or Statements

If you have a current Sage 300 install ( I think 2019+) with Multiple Contacts (It might be a subscription feature), it also allows you to enter multiple contacts and there is a switch to include the email when sending A/R Invoices and/or Receipts and/or Statements

This is the way.

Multiple contacts was introduced in Sage 300 2020 product update 1
https://erp-systems.com.my/features/multiple-contacts/

Yes it is a subscription feature. It is well worth moving to subscription to get the new features. No change in Sage setup / environment / data location  etc  - just the licencing.

And if you dont want subscription :
- TaiRox makes a great multiple contacts add-in.
- Key Communications from Pacific Tech does multiple contacts, very flexible.

https://www.acutedata.com/pdf/sage-300/Sage-300-Comparison-Guide-Subscription-vs-Perpetual.pdf