I should also mention that we have uninstalled and reinstalled both FM and Outlook, to no avail.
Have you tried just using the SMTP settings instead? My email program isn't supported on the mac at all, but FMP's SMTP email send option works fine.
(Skip Outlook....just talk to the email server directly with the SMTP option.)
HOPE THIS HELPS.
I'm afraid I have no insights, but would like to know more about your set up. The hospital I work with is transitioning to Office 365 soon and I am collecting all the data points I can about issues that may arise with FileMaker (I don't have the test suite of computers available yet).
Could you share with me what version of 13 your client was using that worked with Office 365, and what flavour of Office 365 it is (cloud-based, Exchange server-based, or something else)? Also, was the FMP 13 the 32 bit install? Were the 14 installs 32 bit?
Thank you for your help and I hope you find a resolution.
Beatrice Beaubien, PhD
FileMaker Business Alliance
FileMaker 15 Certified Developer