When trying to send an email to a case with Send to Case and the Unable to get email information error comes up, close and re-open the Sent to Case panel, and try again. Sometimes, it helps to give it some time before trying again.
This error occurs when we try to get the data from the email and it fails.
If it always fails on a specific email, please forward that email to Gardiant Works support so we can try to find out what’s going on with it in particular. By examining the email in question, we might be able to find out if there is an element (link, character, etc.) in the email that affects the process of getting the data.