What does priorities mean in an email?

Answer 1

Priority in the email indicates the importance of the message. The message can be high, low or with a normal priority. If the message is with a high priority, it is often indicated with a red exclamation mark. That allows the reader notice this message more easily. Of course, the notification depends on the reader's email client. Sometimes the important messages may be displayed in red and messages with low importance may be grayed out. The priority also does not indicate how important the message is to the reader. It only indicates how important the message was to the sender. Reader may find the message unimportant and mark it accordingly.

Answer 2

I think the original idea was that messages with highest priority were given .. err.. "highest priority" on their way to the recipient. For instance, intermediate server machines, with a lot of work to do, can start with those high-priority messages. But I don't think that any machine takes that this label into account (as email is free, all of us will say my message is very important, if this would help).

However, as the message contain the priority label, email readers show it. You can use the priority to inform the recipient is the email is urgent: maybe s/he will get many unread messages but your will get a red exclamation mark.

Answer 3

It's a way to mark a message as especially important.

Answer 4

It is a way for the sender to notify the receiver that this particular message has high importance, or there may be some time urgency in reading the message.