Dear You, the Person Who's About to Reply to All in an E-mail,
Stop! Before you hit send, is that e-mail relevant to everyone on the list? Are you just talking to talk, or are you adding to the conversation?
If it's the former, please (PLEASE) think long and hard before you hit "reply to all." Yes, sometimes joking is fun for everyone to read. Yes, sometimes it's good to make the joke and let off a little steam, if you need to. But if you're a habitual reply-to-all joke maker, maybe you should cut it down to maybe one joke every few days, instead of a few jokes every day.
Your recipients' inboxes will thank you for it.
*Giving credit where it's due: This phrase is slightly modified from one used by the awesome people at TBTL.