In my solution, a 'Send Mail' script step that includes specification of an attachment works in OS 10.10.5, but fails to include the attachment when sending mail in a 10.12.6 environment. A client reported this to me.
I have verified this report and have tested the exact same code (FMPA 13) in both environments. 10.12.6 clearly handles the 'send mail' script step when using the 'via Email client' option differently from 10.10.5.
Is this a known issue with the send mail script step? Is there a workaround?