Nothing. The subject line is optional.
A sentence describing why you are sending the e-mail
A short phrase (3-5 words) describing the reason for your e-mail
Only your name
No more than one word, like "Help" or "Hello"
When sending a message to friends and family
When sending a message to a teacher
When sending a message to an employer or a potential employer
Never. E-mail recipients do not expect you to use correct grammar or spelling.
Always, regardless of who will receive your message or how they are related to you.
The person receiving the message may believe that you are are angry and shouting at them.
The recipient may believe that you cannot use the SHIFT key correctly on the keyboard.
The recipient may believe that you do not know how to use capitalization correctly in English.
The recipient will see and reply to your message faster than if you key using appropriate letter case.
Forward the message to your ten best friends, asking them to do the same because of all the money you received.
Make up ten e-mail addresses to forward it to, so that you can forward the message without bothering anyone you know.
Forward the message to 20 people in your e-mail list at random, just to be sure that ten of them read it.
Delete the message as junk mail.
You should reply to all e-mail immediately after you receive it, even if you don't have a good reply.
You should reply to e-mail within 24-48 hours, taking time to formulate an appropriate reply when necessary.
You should wait at least a week. The person sending the e-mail may find the answer on their own if you wait long enough.
You should find time to talk to the person face-to-face or in person before replying to the e-mail.
When you see the person again face-to-face.
When the person calls you using the phone number you provided in the e-mail message.
Through the same e-mail account you used to send the original message.
Check your Sent Items folder to make sure that you sent the message to the correct e-mail address.
Resend your original message to the same person, noting that you are resending it because you are afraid they did not receive it.
Send a short, new message that simply asks the person why they haven't replied to your earlier message.
Complain to anyone you feel ought to know that the person you sent the message to never replies to e-mail messages.
It is always acceptable to forward an e-mail message, as long as the contents are important to the people who will receive the forwarded message.
Because the content of any e-mail message is automatically copyrighted by US Copyright law, you should never forward an e-mail without the original author's permission.
You should never forward e-mail messages for any reason. This is considered spam.
You should forward e-mail only after you have removed all text that identifies the original sender of the message.
Only if the attached file includes information that cannot be included in the e-mail message itself, such as an Excel file or a screen shot of an error message.
You should always attach a photo of yourself to every e-mail message you send.
It is never appropriate to attach a file to an e-mail message.
If you have keyed the text you want to send in a Wordpad file, and you don't want to have to re-key the text in the e-mail body.
Verify that the recipient will receive your attachment.
Include an appropriate subject line and text in the body of the message, so that the recipient knows what the attachment is.
Compress the file (or compress a folder if there are multiple files).
Verify that you are attaching the correct version of the file(s).
If you have written the message in anger, you should save the message instead of sending it. You can re-open the message later when you are in better control of your emotions, and consider sending it after revising it.
You do not have time to finish an e-mail that you have started.
You should use SAVE for every e-mail you send so that you can keep a copy of the message for your records.
You need to print a hard copy of a message you are about to send.
Your reason for sending the e-mail.
Your name at the bottom of the message.
Your phone number.
An alternate e-mail address.
It is acceptable to send a message with the body empty if you use a subject line with enough detail.
Confidential information, like your Social Security number or bank account numbers.
Statements that could be interpreted as illegal or offensive.
Text or pictures from a copyrighted web site.
Change the subject line, if appropriate.
Remove extra text or content not relevant to your reply.
Include quoted text from the original message to give your reply a context (or include that context in your reply).
Delete everything from the original e-mail except your short reply, assuming that the recipient will remember the message you are replying to.
Any time the original e-mail is sent to multiple people.
When everyone who received the original message needs to know your reply.
So that everyone who receives the message knows that you sent a reply.
It is never appropriate to use the Reply to All button to reply to an e-mail message.
Here's an interesting quiz for you.