gmbackup

Simple tool to backup a Gmail account.

• Performs full and incremental sync using the Gmail API.
• Saves only message contents, not metadata such as labels.
• Message saved in EML format, which just the raw email data in RFC2822 format.
• Restore functionality not yet implemented.

Installation

To install gmbackup using Go:

go install github.com/rigtorp/gmbackup@latest

Alternatively, you can build it from source:

git clone https://github.com/rigtorp/gmbackup.git
cd gmbackup
go build .

Creating credentials.json

1. Go to the Google Cloud Console.
2. Create a new project or select an existing one.
3. Search for Gmail API and click Enable.
4. Go to APIs & Services > OAuth consent screen:
   • Select External (or Internal if using Google Workspace) and click Create.
   • Fill in the required fields (App name, User support email, Developer contact information).
   • Click Save and Continue.
   • Under Scopes, click Add or Remove Scopes, search for https://www.googleapis.com/auth/gmail.readonly, check it, and click Add to table. Click Update and then Save and Continue.
   • Under Test users, click Add Users and add your Gmail address. Click Save and Continue.
5. Go to APIs & Services > Credentials:
   • Click Create Credentials > OAuth client ID.
   • Select Application type: Desktop app.
   • Name it (e.g., gmbackup) and click Create.
   • Download the JSON file and rename it to credentials.json.

You can either provide the client credentials JSON file in $XDG_CONFIG_HOME/gmbackup/credentials.json or use the --client-id and --client-secret flags.