Why Did Gmail Mark Conversation as Important?

Google uses complex algorithms to ascertain the importance of an email and makes the reasons easy to see. To get an idea of why Gmail determined an email was important enough to make your Priority Inbox:

Potential Reasons for Categorizing an Email as Important

The reasons Gmail places messages in your Priority Inbox include:

The words in the message. You may have marked similar emails important in the past, or the message urges you to action.The people in the conversation. You exchange emails frequently with the sender or consistently mark their emails as important.Your interaction with messages in the conversation. You’ve taken action on these messages in the past.You marked the message as important.The message was sent only to you. Messages sent to more than one person tend to be lower in importance, while those with only you in the recipient list are seen as important.You often read messages with this label.Gmail’s magic sauce. You may see this for older messages marked as important.

Make the Priority Inbox Marker for Important Messages Visible

To enable the yellow priority tag for messages marked as important in Gmail: