Labels feature in Quickmail allows you to categorize the replies you get from your prospects.

Example: You’ll be able to compare stats of positive vs negative responses

To start:
1. Go to Prospects -> Labels -> Menu -> Create Label

After creating your labels, Go to Settings -> Inbox -> Settings -> click “Check Replies Now”. Wait for the requested process to complete:

2. Sign-in to your Gmail account associated with your Quickmail account. 
You should see a label/folder named "Quickmail". Check the sub-labels to see the labels you made in Quickmail. 

3. Whenever you receive a response from your prospect, you can mark them with the labels nested under "Quickmail". You can also drag and drop the emails.. Example:

4. Every hour, Quickmail will automatically scan your inbox and apply a label to the prospects' conversation Quickmail if their replies are found in the labels in your Gmail account. 

Moving the responses from one label to another will update the label. 
This works the same if you're using an Outlook inbox.

A conversation can also be labeled manually even if the prospect hasn't sent a reply yet.

You can go to Sequence -> Menu -> View Detailed Stats to see stats for each label you synced.

You can also go to Prospects List -> Click "Filter" and filter prospects by their conversation labels.