Is it possible to configure K2 in a way so that the sender email address can be different, depending on the app?
At the moment we have one global sender email address but we would like to know if we can personalise the email notifications, so the user knows which app it has come from.
Is it a case of using environment variables? If so, does this work everywhere? As in within a workflow, on a Form etc.
Yes, this is possible with on-prem K2 (K2 Cloud is a bit more complicated in this regard). What we do is use environment fields with the "from" address for various apps. Then, when the workflow is sending an e-mail, we configure the "from" address to use the appropriate environment field. Hope this helps...
It depends. If you are using SmartActions (where you respond to a task via email to action it), then all tasks will send from that account. K2 will not honor any manually configured From Address in tasks in that scenario. You can still modify the From Address in Email steps.
If you are not using SmartActions, then you CAN modify the From Address. If you are using Exchange Web Services for sending email, then you may need to grant the K2 Service Account permissions to Send As or Send on Behalf of the account.