fix(groupware): Move admin and user documentation for mail app out of mail repo and update debug logging

Signed-off-by: David Dreschner <github-2017@dreschner.net>

Author: DerDreschner

admin_manual/groupware/mail.rst

@@ -2,6 +2,119 @@
 Mail
 ====
 
+Configuration
+-------------
+
+Anti-abuse alerts
+^^^^^^^^^^^^^^^^^
+
+The app can write alerts to the logs when users send messages to a high number of recipients or sends a high number of messages for a short period of time. These events might indicate that the account is abused for sending spam messages.
+
+To enable anti-abuse alerts, you'll have to set a few configuration options :doc:`via occ  <../occ_command>` .
+
+::
+
+    # Turn alerts on
+    occ config:app:set mail abuse_detection --value=on
+    # Turn alerts off
+    occ config:app:set mail abuse_detection --value=off
+
+    # Alert when 50 or more recipients are used for one single message
+    occ config:app:set mail abuse_number_of_recipients_per_message_threshold --value=50
+
+    # Alerts can be configured for three intervals: 15m, 1h and 1d
+    # Alert when more than 10 messages are sent in 15 minutes
+    occ config:app:set mail abuse_number_of_messages_per_15m --value=10
+    # Alert when more than 30 messages are sent in one hour
+    occ config:app:set mail abuse_number_of_messages_per_1h --value=30
+    # Alert when more than 100 messages are sent in one day
+    occ config:app:set mail abuse_number_of_messages_per_1d --value=100
+
+Attachment size limit
+^^^^^^^^^^^^^^^^^^^^^
+
+Admins can prevent users from attaching large attachments to their emails. Users will be asked to use link shares instead.
+
+::
+
+    'app.mail.attachment-size-limit' => 3*1024*1024,
+
+The unit is bytes. The example about with limit to 3MB attachments. The default is 0 bytes which means no upload limit.
+
+Background sync interval
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+Configure how often Mail keeps users' mailboxes updated in the background in seconds. Defaults to 3600, minimum 300.
+
+::
+
+    'app.mail.background-sync-interval' => 7200,
+
+Disable TLS verification for IMAP/SMTP
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Turn off TLS verification for IMAP/SMTP. This happens globally for all accounts and is only needed in edge cases like with email servers that have a self-signed certificate.
+
+::
+
+    'app.mail.verify-tls-peer' => false
+
+Google OAuth
+^^^^^^^^^^^^
+
+This app can allow users to connect their Google accounts with OAuth. This makes it possible to use accounts without 2FA or app password.
+
+1. `Create authorization credentials <https://developers.google.com/identity/protocols/oauth2/web-server#prerequisites>`_. You will receive a client ID and a client secret.
+2. Open the Nextcloud settings page. Navigate to *Groupware* and scroll down to *Gmail integration*. Enter and save the client ID and client secret.
+
+Local IMAP and SMTP servers
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+By default, Nextcloud does not allow local hostnames and IP addresses as remote servers. This includes IMAP, SMTP and Sieve servers
+like ``localhost``, ``mx.local`` and ``10.0.0.3``. This check can be disabled with via ``config/config.php``.
+
+::
+
+    'allow_local_remote_servers' => true,
+
+Timeouts
+^^^^^^^^
+
+Depending on your mail host, it may be necessary to increase your IMAP and/or SMTP timeout threshold.
+Currently IMAP defaults to 5 seconds and SMTP defaults to 20 seconds. They can be changed as follows:
+
+IMAP timeout
+~~~~~~~~~~~~
+
+::
+
+    'app.mail.imap.timeout' => 5
+
+SMTP timeout
+~~~~~~~~~~~~
+
+::
+
+    'app.mail.smtp.timeout' => 20
+
+Sieve timeout
+~~~~~~~~~~~~~
+
+::
+
+    'app.mail.sieve.timeout' => 5
+
+Use php-mail for sending mail
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. warning:: Support for using php-mail was removed in version 4.4 of the mail app!
+
+You can use the php-mail function to send mails. This is needed for some web hosters (1&1 (1und1)).
+
+::
+
+    'app.mail.transport' => 'php-mail'
+
 Account delegation
 ------------------
 
@@ -25,56 +138,49 @@ XOAUTH2 Authentication with Microsoft Azure AD
 
 The Mail app supports XOAUTH2 authentication with hosted Microsoft Outlook accounts. An app has to be registered in the Microsoft Azure web interface and its credentials have to be supplied to the Nextcloud instance. You can find relevant settings in the Groupware section of the admin settings.
 
-Step 1: Open the Azure AD Dashboard
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+**Step 1: Open the Azure AD Dashboard**
 
 Visit the `Azure portal <https://portal.azure.com>`_ and navigate to the Azure AD dashboard.
 
 .. figure:: images/azure_xoauth2/1.png
 
-Step 2: Create a new app registration
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+**Step 2: Create a new app registration**
 
 .. figure:: images/azure_xoauth2/2.png
 
 Chose a name, allow organizational and personal Microsoft accounts. Configure a web app and copy the redirect URI from the groupware settings of your Nextcloud instance. Have a look at step 8 on where to find the redirect URI. Finally, click on register to proceed.
 
 .. figure:: images/azure_xoauth2/3.png
 
-Step 3: Copy the client ID
-~~~~~~~~~~~~~~~~~~~~~~~~~~
+**Step 3: Copy the client ID**
 
 This ID will be needed later for the Nextcloud settings.
 
 .. figure:: images/azure_xoauth2/4.png
 
-Step 4: Create a new client secret
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+**Step 4: Create a new client secret**
 
 .. figure:: images/azure_xoauth2/5.png
 
 Chose a descriptive name for the secret and set the an appropriate expiration date. Click on add to create the secret.
 
 .. figure:: images/azure_xoauth2/6.png
 
-Step 5: Copy the client secret
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+**Step 5: Copy the client secret**
 
 Copy the client secret manually or by clicking on the copy button. You can find it in the value column. The secret will also be needed later for the Nextcloud settings.
 
 .. figure:: images/azure_xoauth2/7.png
 
-Step 6: Configure Nextcloud
-~~~~~~~~~~~~~~~~~~~~~~~~~~~
+**Step 6: Configure Nextcloud**
 
 Open the groupware settings in the Nextcloud admin settings and fill in the client ID and client secret. Leave the tenant ID as is (common). You can also find the redirect URI here. Click on save to proceed.
 
 .. warning:: Using a custom tenant ID is not covered by this guide. Only configure it if you are an expert and changed the supported account types in step 2.
 
 .. figure:: images/azure_xoauth2/8.png
 
-Step 7: Connect Microsoft Outlook accounts
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+**Step 7: Connect Microsoft Outlook accounts**
 
 Congratulations! You are now able to use hosted Microsoft Outlook accounts in the Mail app. Use your Microsoft account email and any password when adding your account. The password will be discarded and you will be prompted with a Microsoft consent popup to log in to your account.