Five annoying e-mail habits (what we can do about them!).

1. Vague or nonexistent subject line
   Make it easy for recipients to know what your message is about. If you're like most people, you have an in-basket that summarizes your incoming messages, probably by date, sender, and subject. Isn't it wonderful when you can get the information you need simply from the subject line? The sender has made it easy for you and has saved you time.
   
   
2. Changing the topic without changing the subject
   E-mail users do this all too often, usually out of laziness.
   e.g. you send a note to a colleague about subject 1. That colleague later needs to send a note to you on subject 2. However, instead of creating a new email, labeling it "subject 2," he/she simply replies to you, discusses subject 2, but keeps the subject line as "subject 1."
   Annoying, isn't it?
   When you send e-mail, make sure the subject line matches the actual subject. If you're going to send a note via a reply, change the subject line to match the actual subject.
   
   
3. Including multiple subjects in one email
   Covering multiple topics in one email involves less sending and hence less e-mail traffic and volume. However, your recipient might overlook one or more of those topics. It's better to keep to one topic per message.
   
   
4. Sending before thinking
   When you were small, your mum probably told you to count to ten before responding to someone. Why did she say that? She knew that answering before thinking can lead to problems.
   Make sure you really mean to say what you've written. People can interpret your words differently from what you meant. A statement made in jest to someone via e-mail may have a greater chance of being misinterpreted than one made in person (you could consider WaxMail: http://www.waxmail.biz/ ). Also, be careful about reacting and replying too quickly to an e-mail that upsets you.
   Legal implications offer another reason to think before sending. E-mail can be subject to "discovery" ("The compulsory disclosure of pertinent facts or documents to the opposing party in a civil action, usually before a trial begins.") by lawyers for a party that might be suing your employer. That is, the things you write in your e-mail could end up in the hands of those lawyers and could be used as evidence against your company in a trial. So before you send an e-mail, imagine that you're on a witness stand having to explain it.
   
   
5. Inadvertent replying to all
   Before hitting Reply To All, make sure you really need to do so. Does everyone need to see your response? Does your response benefit everyone else? Or are you sending merely a private response or addressing a personal issue with the sender? In these situations, it's better just to do a simple Reply. Otherwise, a private disagreement becomes public (and embarrassing) knowledge.
   Be aware that if you receive a message because you're part of certain message groups (e.g., a JISCmail group), your reply might go to everyone in the group even if you just hit Reply.

Do you recognize yourself in any of these mistakes?

The good news is that once you recognize these issues, it's easy to address them.