System Five is capable of having more than 1 email address saved on the Customer or Supplier record, separated by a ";". That has stopped working but is now fixed on V 22.214.171.124 or the latest.
Have System Five updated to the latest release
Login to System5 > Setup Tools > Configuration > Setup Registry
Click YES button on the prompt
- And if you don't see "MultipleEmails" entry? You can manually create it
- while FEATUREFLAG selected
- Click on the "NEW" button up top
- Under Level-2 Desc field
- Type in "MultipleEmails" and leave everything as is and click on the OK button
- Now you should see that entry from the list
- Double-click it and set Edit Key field = Y
- click OK
- and you are done.