I'm trying to specify a custom email address in the 'From' field of a 'Send Email' action in K2 for SharePoint on 4.6.10. If I change it to anything other than the default (i.e. the Environment Field > Mail Server > From Address - which is currently set to the K2 Service account for this environment), then the 'Send Mail' action fails.
I've tried several addresses that I know to be valid, including my own.
Can anyone advise what might be going wrong?
Thanks,
Steve