In Gmail, labels attach to individual messages, not whole threads. This means that new arriving messages in a thread will not always be given existing labels unless they are manually reapplied.

To work around this issue, this project uses a Google Apps Script to periodically add missing labels to all messages affected.

Installation

1. Enable the Google Apps Script API at https://script.google.com/home/usersettings
2. Create a new project at https://script.google.com/home
3. Clone or download this repository

   git clone [email protected]:ariasemis/propagate-gmail-label.git

4. Edit .clasp.json file with the scriptId of the project you created
5. Push changes to google apps script project

   npm install 
   npx clasp login # access your Google account
   npm run push

6. Open project on script.google.com and run install function

To stop the script from running you can execute the uninstall function provided in the script.

Settings

The following options can be configured in Project Settings>Script Properties:

Property	Default Value	Description
DAYS_BETWEEN_RUNS	1	Frequency in days at which the script will run
TIME_OF_DAY_TO_RUN	5	Specifies the hour at which the script runs
DRY_RUN	false	When true, the script will only log results without applying changes to message labels
MAX_THREADS_PER_RUN	20	Maximum number of message threads to process per run
NO_LABEL	uncategorized	Name of the label to add to threads without any label

Acknowledgements

Inspired by Tom Scott's post on fixing Gmail labels.