Workflow - Email Contact linked to Account

[khopper]

I am trying to setup a Workflow to email a contact that is linked to an account OR from a custom field with an email address in an account.
I do not see any way to do this. Is it even possible? I do not want to specify a contact since it can be different between accounts.

Version 5.0.5
AP Version 1.30.1

[tanya]

Hello,
only email address field is available for Send Email in Workflow, no custom varchar field