When
you need input on new list items from people outside the
tenant, you can let a flow send an e-mail with an item description
and "vote" buttons. The flow can also send the votes back
to the list.
In this article Peter Kalmström, kalmstrom.com CEO and Systems
Designer, shows how an e-mail input flow can be used for
approvals from a legal department that not yet use SharePoint.
Each time a new project is added to a "Projects" list, and
e-mail with three options is sent to the legal department
automatically. The responsible person at the legal department
clicks on the "Approved", "Rejected" or "Need More Info"
button, and that input is sent back to a "Legal approval"
column in the Projects list.
Flow steps
Create a blank flow and use the trigger SharePoint
- when an item is created' for the Projects list.
Add the action Office 365 Outlook, send email with
options.
Fill out the e-mail details:
Receiver e-mail address.
Subject: general text, for example New project
for approval + the dynamic content Project Title.
Fill out the options with comma between them:
Approved, Rejected, Need More Info.
Add the dynamic content Project Description
in the body.
Add the action 'SharePoint, update item? for the
Projects list.
At Id, add the dynamic content ID.
At Legal Approval add the dynamic content SelectedOption.
That will put the response from the Legal department
in the SharePoint list.
Remove all the default options so that all other
fields are blank.
When
you need input on new list items from people outside the
tenant, you can let a flow send an e-mail with an item description
and "vote" buttons. The flow can also send the votes back
to the list. 
