Gmail made some changes to its "muting" feature that help you keep you inbox empty from the mailing lists:
"Smart Mute," a new Gmail Labs feature helps to solve the problem of conversations that just won't die. "If you enable "Smart Mute" from the Labs tab in Gmail Settings, muted conversations will only appear in your inbox if a new message in the conversation is addressed to you and no one else, or a new email in the conversation adds you to "To" or "Cc" line. Once you enable Smart Mute, mute behavior will change across all versions of Gmail: web, mobile, Android, etc. Try it out and let us know what you think," explains Google.
Also added two new easier ways to unmute muted conversations. The first is through an "Unmute" option in the "More actions" menu. You'll see this when you view or select a muted conversation.
If you're viewing a muted conversation, you'll see the second new way to unmute: the "Muted" label next to the subject line now behaves just like all other labels. Clicking on the "X" will remove the Muted label and unmute the conversation.