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. 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, Google Apps, 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 / Google Apps with Reply by email, make sure you have IMAP access enabled and allow less secure apps to access the account.

To set up a basic Postfix mail server with IMAP access on Ubuntu, follow these instructions.

Set it up

Omnibus package installations

Find the incoming_email section in /etc/gitlab/gitlab.rb, enable the feature and fill in the details for your specific IMAP server and email account:

# Configuration for Postfix mail server, assumes mailbox incoming@gitlab.example.com
gitlab_rails['incoming_email_enabled'] = true

# The email address including a placeholder for the key that references the item being replied to.
# The `%{key}` placeholder is added after the user part, before the `@`.
gitlab_rails['incoming_email_address'] = "incoming+%{key}@gitlab.example.com"

# Email account username
# With third party providers, this is usually the full email address.
# With self-hosted email servers, this is usually the user part of the email address.
gitlab_rails['incoming_email_email'] = "incoming"
# Email account password
gitlab_rails['incoming_email_password'] = "[REDACTED]"

# IMAP server host
gitlab_rails['incoming_email_host'] = "gitlab.example.com"
# IMAP server port
gitlab_rails['incoming_email_port'] = 143
# Whether the IMAP server uses SSL
gitlab_rails['incoming_email_ssl'] = false
# Whether the IMAP server uses StartTLS
gitlab_rails['incoming_email_start_tls'] = false

# The mailbox where incoming mail will end up. Usually "inbox".
gitlab_rails['incoming_email_mailbox_name'] = "inbox"

# Configuration for Gmail / Google Apps, assumes mailbox gitlab-incoming@gmail.com
gitlab_rails['incoming_email_enabled'] = true

# The email address including the `%{key}` placeholder that will be replaced to reference the item being replied to.
# The `%{key}` placeholder is added after the user part, after a `+` character, before the `@`.
gitlab_rails['incoming_email_address'] = "gitlab-incoming+%{key}@gmail.com"

# Email account username
# With third party providers, this is usually the full email address.
# With self-hosted email servers, this is usually the user part of the email address.
gitlab_rails['incoming_email_email'] = "gitlab-incoming@gmail.com"
# Email account password
gitlab_rails['incoming_email_password'] = "[REDACTED]"

# IMAP server host
gitlab_rails['incoming_email_host'] = "imap.gmail.com"
# IMAP server port
gitlab_rails['incoming_email_port'] = 993
# Whether the IMAP server uses SSL
gitlab_rails['incoming_email_ssl'] = true
# Whether the IMAP server uses StartTLS
gitlab_rails['incoming_email_start_tls'] = false

# The mailbox where incoming mail will end up. Usually "inbox".
gitlab_rails['incoming_email_mailbox_name'] = "inbox"

As mentioned, the part after + in the address is ignored, and any email sent here will end up in the mailbox for incoming@gitlab.example.com/gitlab-incoming@gmail.com.

Reconfigure GitLab for the changes to take effect:
```
sudo gitlab-ctl reconfigure
```
Verify that everything is configured correctly:
```
sudo gitlab-rake gitlab:incoming_email:check
```
Reply by email should now be working.

Installations from source

Go to the GitLab installation directory:
```
cd /home/git/gitlab
```

Find the incoming_email section in config/gitlab.yml, enable the feature and fill in the details for your specific IMAP server and email account:

sudo editor config/gitlab.yml

# Configuration for Postfix mail server, assumes mailbox incoming@gitlab.example.com
incoming_email:
  enabled: true

  # The email address including the `%{key}` placeholder that will be replaced to reference the item being replied to.
  # The `%{key}` placeholder is added after the user part, after a `+` character, before the `@`.
  address: "incoming+%{key}@gitlab.example.com"

  # Email account username
  # With third party providers, this is usually the full email address.
  # With self-hosted email servers, this is usually the user part of the email address.
  user: "incoming"
  # Email account password
  password: "[REDACTED]"

  # IMAP server host
  host: "gitlab.example.com"
  # IMAP server port
  port: 143
  # Whether the IMAP server uses SSL
  ssl: false
  # Whether the IMAP server uses StartTLS
  start_tls: false

  # The mailbox where incoming mail will end up. Usually "inbox".
  mailbox: "inbox"

# Configuration for Gmail / Google Apps, assumes mailbox gitlab-incoming@gmail.com
incoming_email:
  enabled: true

  # The email address including the `%{key}` placeholder that will be replaced to reference the item being replied to.
  # The `%{key}` placeholder is added after the user part, after a `+` character, before the `@`.
  address: "gitlab-incoming+%{key}@gmail.com"

  # Email account username
  # With third party providers, this is usually the full email address.
  # With self-hosted email servers, this is usually the user part of the email address.
  user: "gitlab-incoming@gmail.com"
  # Email account password
  password: "[REDACTED]"

  # IMAP server host
  host: "imap.gmail.com"
  # IMAP server port
  port: 993
  # Whether the IMAP server uses SSL
  ssl: true
  # Whether the IMAP server uses StartTLS
  start_tls: false

  # The mailbox where incoming mail will end up. Usually "inbox".
  mailbox: "inbox"

As mentioned, the part after + in the address is ignored, and any email sent here will end up in the mailbox for incoming@gitlab.example.com/gitlab-incoming@gmail.com.

Enable mail_room in the init script at /etc/default/gitlab:

sudo mkdir -p /etc/default
echo 'mail_room_enabled=true' | sudo tee -a /etc/default/gitlab

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

Verify that everything is configured correctly:

sudo -u git -H bundle exec rake gitlab:incoming_email:check RAILS_ENV=production

Reply by email should now be working.

Development

Go to the GitLab installation directory.

Find the incoming_email section in config/gitlab.yml, enable the feature and fill in the details for your specific IMAP server and email account:

# Configuration for Gmail / Google Apps, assumes mailbox gitlab-incoming@gmail.com
incoming_email:
  enabled: true

  # The email address including a placeholder for the key that references the item being replied to.
  # The `%{key}` placeholder is added after the user part, before the `@`.
  address: "gitlab-incoming+%{key}@gmail.com"

  # Email account username
  # With third party providers, this is usually the full email address.
  # With self-hosted email servers, this is usually the user part of the email address.
  user: "gitlab-incoming@gmail.com"
  # Email account password
  password: "[REDACTED]"

  # IMAP server host
  host: "imap.gmail.com"
  # IMAP server port
  port: 993
  # Whether the IMAP server uses SSL
  ssl: true
  # Whether the IMAP server uses StartTLS
  start_tls: false

  # The mailbox where incoming mail will end up. Usually "inbox".
  mailbox: "inbox"

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

Uncomment the mail_room line in your Procfile:

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

Restart GitLab:
```
bundle exec foreman start
```