When you save a draft message, we send the save command to your email provider’s server. The save command is relayed to the email provider’s server. Once the email is saved, your provider sends the information back to Inky to show the email in the Draft folder for that email provider. You can click on the Draft folder in Inky to see all of your draft messages for all of your accounts in one place. Alternatively, you can select the account and then click on the Draft folder to display that account's draft messages.
It does take some time for Inky to fetch these saved draft messages, but they'll eventually show up. Moreover, you can check in your email provider’s interface to see that the message is not lost.