Reply by email

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

In order to do this, you need access to an IMAP-enabled email account, with a provider or server that supports email 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.

Set it up

In this example, we'll use the Gmail address gitlab-replies@gmail.com. If you're actually using Gmail with Reply by email, make sure you have IMAP access enabled and allow less secure apps to access the account.

Installations from source

Go to the GitLab installation directory:
```
cd /home/git/gitlab
```
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:
```
sudo editor config/gitlab.yml
```
```
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.
Find config/mail_room.yml.example and copy it to config/mail_room.yml:
```
sudo cp config/mail_room.yml.example config/mail_room.yml
```

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

sudo editor config/mail_room.yml

: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
    # Always true.
    :delete_after_delivery: true
    :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

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

Edit /etc/default/gitlab to enable mail_room:

sudo editor /etc/default/gitlab

mail_room_enabled=true

Restart GitLab:
```
sudo service gitlab restart
```

Check if everything is configured correctly:

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

Reply by email should now be working.

Omnibus package installations

TODO

Development

Go to the GitLab installation directory.
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:
```
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.
Find config/mail_room.yml.example and copy it to config/mail_room.yml:
```
sudo cp config/mail_room.yml.example config/mail_room.yml
```