# Reply by email

GitLab can be set up to allow users to comment on issues and merge requests by replying to notification emails.

## Get a mailbox

Reply by email requires an IMAP-enabled email account, with a provider or server that supports [email sub-addressing](https://en.wikipedia.org/wiki/Email_address#Sub-addressing). Sub-addressing is a feature where any email to `user+some_arbitrary_tag@example.com` will end up in the mailbox for `user@example.com`, and is supported by providers such as Gmail, Yahoo! Mail, Outlook.com and iCloud, as well as the Postfix mail server which you can run on-premises.

If you want to use Gmail with Reply by email, make sure you have [IMAP access enabled](https://support.google.com/mail/troubleshooter/1668960?hl=en#ts=1665018) and [allow less secure apps to access the account](https://support.google.com/accounts/answer/6010255).

To set up a basic Postfix mail server with IMAP access on Ubuntu, follow [these instructions](./postfix.md).

## Set it up

In this example, we'll use the Gmail address `gitlab-replies@gmail.com`. 

### Installations from source

1. Go to the GitLab installation directory:

    ```sh
    cd /home/git/gitlab
    ```

1. Find the `reply_by_email` section in `config/gitlab.yml`, enable the feature and enter the email address including a placeholder for the `reply_key`:

    ```sh
    sudo editor config/gitlab.yml
    ```
    
    ```yaml
    reply_by_email:
      enabled: true
      address: "gitlab-replies+%{reply_key}@gmail.com"
    ```

    As mentioned, the part after `+` is ignored, and this will end up in the mailbox for `gitlab-replies@gmail.com`.

2. Find `config/mail_room.yml.example` and copy it to `config/mail_room.yml`:
    
    ```sh
    sudo cp config/mail_room.yml.example config/mail_room.yml
    ```

3. Uncomment the configuration options in `config/mail_room.yml` and fill in the details for your specific IMAP server and email account:

    ```sh
    sudo editor config/mail_room.yml
    ```

    ```yaml
    :mailboxes:
      -
        # IMAP server host
        :host: "imap.gmail.com"
        # IMAP server port
        :port: 993
        # Whether the IMAP server uses SSL
        :ssl: true
        # Email account username. Usually the full email address.
        :email: "gitlab-replies@gmail.com"
        # Email account password
        :password: "[REDACTED]"
        # The name of the mailbox where incoming mail will end up. Usually "inbox".
        :name: "inbox"
        # Always "sidekiq".
        :delivery_method: sidekiq
        :delivery_options:
          # The URL to the Redis server used by Sidekiq. Should match the URL in config/resque.yml.
          :redis_url: redis://localhost:6379
          # Always "resque:gitlab".
          :namespace: resque:gitlab
          # Always "incoming_email".
          :queue: incoming_email
          # Always "EmailReceiverWorker"
          :worker: EmailReceiverWorker
    ```


4.  Find `lib/support/init.d/gitlab.default.example` and copy it to `/etc/default/gitlab`:
    
    ```sh
    sudo cp lib/support/init.d/gitlab.default.example /etc/default/gitlab
    ```

5. Edit `/etc/default/gitlab` to enable `mail_room`:

    ```sh
    sudo editor /etc/default/gitlab
    ```
    
    ```sh
    mail_room_enabled=true
    ```

6. Restart GitLab:
    
    ```sh
    sudo service gitlab restart
    ```

7. Check if everything is configured correctly:

    ```sh
    sudo bundle exec rake gitlab:reply_by_email:check RAILS_ENV=production
    ```

8. Reply by email should now be working.

### Omnibus package installations

TODO

### Development

1. Go to the GitLab installation directory.

1. Find the `reply_by_email` section in `config/gitlab.yml`, enable the feature and enter the email address including a placeholder for the `reply_key`:
    
    ```yaml
    reply_by_email:
      enabled: true
      address: "gitlab-replies+%{reply_key}@gmail.com"
    ```

    As mentioned, the part after `+` is ignored, and this will end up in the mailbox for `gitlab-replies@gmail.com`.

2. Find `config/mail_room.yml.example` and copy it to `config/mail_room.yml`:
    
    ```sh
    sudo cp config/mail_room.yml.example config/mail_room.yml
    ```

3. Uncomment the configuration options in `config/mail_room.yml` and fill in the details for your specific IMAP server and email account:

    ```yaml
    :mailboxes:
      -
        # IMAP server host
        :host: "imap.gmail.com"
        # IMAP server port
        :port: 993
        # Whether the IMAP server uses SSL
        :ssl: true
        # Email account username. Usually the full email address.
        :email: "gitlab-replies@gmail.com"
        # Email account password
        :password: "[REDACTED]"
        # The name of the mailbox where incoming mail will end up. Usually "inbox".
        :name: "inbox"
        # Always "sidekiq".
        :delivery_method: sidekiq
        :delivery_options:
          # The URL to the Redis server used by Sidekiq. Should match the URL in config/resque.yml.
          :redis_url: redis://localhost:6379
          # Always "resque:gitlab".
          :namespace: resque:gitlab
          # Always "incoming_email".
          :queue: incoming_email
          # Always "EmailReceiverWorker"
          :worker: EmailReceiverWorker
    ```

4. Uncomment the `mail_room` line in your `Procfile`:

    ```yaml
    mail_room: bundle exec mail_room -q -c config/mail_room.yml
    ```

6. Restart GitLab:
    
    ```sh
    bundle exec foreman start
    ```

7. Check if everything is configured correctly:

    ```sh
    bundle exec rake gitlab:reply_by_email:check RAILS_ENV=development
    ```

8. Reply by email should now be working.