Recently the Gmail Team updated the list of keyboard shortcuts for the online email client. There’s quite a few new ones such as shortcuts for Mute, Save Draft and Delete plus a few others.
m – Mute
Archives the conversation, and all future messages skip the Inbox unless sent or cc’d directly to you. Learn more.
u – Return to conversation list
Refreshes your page and returns you to the inbox, or list of conversations.
y then o – Archive and next
Archive your conversation and move to the next one.
You can instantly navigate to the Inbox, Contacts, Drafts or your Starred messages by using the shortcut, g, before a corresponding letter, i c d or s.
What are the keyboard shortcuts? – [Gmail]