Using Apple's Shortcuts app, create a new shortcut and set its name to Mail Drop.
Tap in the settings button in the upper right and toggle the "Show in Share Sheet" option.
Tap in the Any button in the action, deselect everything and select only Text.
Using the search bar in the bottom, look for the "Add New Reminder" action and tap on it.
Then, tap in the Reminder button and select the "Shortcut input" variable.
Tap on the plus sign in the top right corner of the Notifications tab in Pushcut.
Name the new notification, then tap on Default Action.
Tap on the "No shortcut" row to select our shortcut.
Use the search bar to look for the Mail Drop shortcut, then select it.
Tap on Done in the Default Action selection view.
Tap on Add then on Done in the top right corner.
Using the IFTTT app or website, create a new Applet.
Tap in the Add button inside the "If Then" section, then search for email.
IFTTT provides two different email triggers. Let's use the first one: "Send IFTTT any email".
Follow the onscreen steps to connect your email to IFTTT.
Tap in the Add button inside the "Then That" section.
Search for Pushcut in the search bar then tap on it.
Tap on the "Send a notification" action.
Follow the onscreen steps to connect Pushcut to your IFTTT account.
Select the "Mail Drop" notification we've just created in the "Which notification" field.
Scroll down and remove all text from the Input field, except the Subject marker.
This input is going to be passed from IFTTT to Pushcut. Then, when we tap on our notification, this same input will be passed to the Mail Drop shortcut.
Tap on Create Action, then in Continue on the next screen.
Check the description of your new applet, and notice it'll work when sending emails from your connected account to IFTTT's trigger email: email@example.com.
Tap on Finish to create your Applet.
Send an email from the address you've connected in step 14 and see the Pushcut notification pop up.
When you tap the notification, the default action will be activated. It'll call our new shortcut and add the email subject as a new reminder!