Google Mail has a few features that can be somewhat confusing if someone is used to Microsoft Outlook, or a similar mail program.
These settings are "Conversation View", "Send & Archive" and "Priority Inbox"
You can change these settings by going to the gear in the upper right corner of Gmail, clicking "Settings" and then finding the settings listed above on the "General" tab.
Conversation View
The settings under "Conversation view" group all email messages that have the same sender(s) and same subject together as a list of messages, as opposed to listing each message separately.
- If you'd like to keep just the original email in the inbox, and not see all messages from that conversation grouped together, turn off "Conversation view".
Send & Archive
The settings under "Send & Archive" enable or disable the "Send & Archive" button on replies.
- When enabled, this button not only sends the reply, but also archives the conversation. Archiving takes the messages out of the inbox, but they're still saved in "All Mail" and "Sent".
- When conversation view is turned on, the "Send & Archive" button removes the entire conversation from the inbox after sending a reply.
- To keep the original message in the inbox when replying, disable the "Send & Archive" button. This will keep the original email and the reply, grouped together in the inbox.
Priority Inbox
The settings for Priority Inbox are found under Settings> Inbox > Inbox Type. This setting controls how messages are organized in the inbox.
- The available options are:
- Default -- Messages are organized in the inbox by the date & time they were received
- Important First -- Messages that Google thinks are important are kept by themselves in a special area near the top of the inbox. Other messages are kept in a separate section of the inbox below, labelled "Everything Else"
- Unread First -- Unread messages are kept by themselves in a special area near the top of the inbox. Other messages are kept in a separate section of the inbox below, labelled "Everything Else"
- Starred First -- Starred messages are kept by themselves in a special area near the top of the inbox. Other messages are kept in a separate section of the inbox below, labelled "Everything Else"
- Priority Inbox -- This setting is a combination of the other three. It has categories for Unread, Important, and Starred messages, while any other messages are kept in a separate section of the inbox below, labelled "Everything Else"
- Some of these options (especially "Unread first") can be confusing because messages can seem to disappear, and not be where a you expects them to be. The best setting for someone unfamiliar with Google Mail is "Default".
For more information, look at the Google documentation at the link below:
https://gsuite.google.com/learning-center/products/gmail/choose-inbox-type/#!/