Until a few months ago I used FMPRO 14 Adv. and I have not had any problems sending several emails with attached files using a basic script.
I use OSx High Sierra with 16Gb of RAM which is fast in other tasks.
Since I updated FMPRO 16 in February of this year, the same procedure of sending several emails (one per record found) with an attachment takes a long time. It takes 8 sec to prepare each of the emails in the OsX High Sierra Mail app. If I have to send 200 emails with a different 150Kb pdf, the work takes too long. It was faster with FMPro 14 Adv than with the current FMPro 16.
Somebody know why?