Have GP2016_R2 Workflow setup
Web Services installed and working. Test email from Workflow setup works correctly.
SMTP server is an Office 365 address.
When sending from a workflow users won't get an approval email depending on the user.
client has an on premise exchange server and newer users are setup with Office 365 email accounts.
Legacy users will receive the email if they are assigned the task but O365 email users will not receive the email for approval/rejection
Only difference that i can see is that the users who are O365 DO NOT have an X500 address in their properties.
I have workflow setup in our demo and we use O365. Do not have an Exchange server setup. Works fine.
We have tried changing the smtp to the on premise exchange server with the same result. I have been following the troubleshooting article in the link below and the items to check seem to check out.
https://community.dynamics.com/gp/b/dynamicsgp/posts/workflow-notification-email-troubleshooting