Welcome to the forum, @Alexander_Davies! I assume you’re talking about modifying ▶️ How to email a "Note to Self" to your Obsidian vault, correct? If so, take a look at the last action, the Create Note block. Currently, it says “Create note [(Mail Subject)] …” — change that to “Create note [INBOX/(Mail Subject)] …”. You’ll have to place the cursor in front of the “Mail Subject” variable, which can be a bit fiddly but it can be done 
HTH!