Merge branch 'html_welcome_mail' into 'stable-3.1'

Allow HTML based welcome messages

I needed a HTML based welcome message, so I added this to mail_plugin.inc.php 

I hope this is the correct approach.

In addition to /conf-custom/mail/welcome_email_DOMAINNAME.txt and /conf-custom/mail/welcome_email_LANGUAGE.txt one may place a /conf-custom/mail/welcome_email_DOMAINNAME.html or /conf-custom/mail/welcome_email_LANGUAGE.html file to allow HTML based welcome messages.

See merge request !276

Author: Marius Burkard

LICENSE

@@ -0,0 +1,25 @@
+Copyright (c) 2007-2016, Till Brehm, ISPConfig UG
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright notice,
+      this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright notice,
+      this list of conditions and the following disclaimer in the documentation
+      and/or other materials provided with the distribution.
+    * Neither the name of ISPConfig nor the names of its contributors
+      may be used to endorse or promote products derived from this software without
+      specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

README.md

@@ -0,0 +1,10 @@
+# ISPConfig - Hosting Control Panel
+
+- Manage multiple servers from one control panel
+- Web server management (Apache2 and nginx)
+- Mail server management (with virtual mail users)
+- DNS server management (BIND and MyDNS)
+- Virtualization (OpenVZ)
+- Administrator, reseller and client login
+- Configuration mirroring and clusters
+- Open Source software (BSD license)

server/plugins-available/mail_plugin.inc.php

@@ -207,7 +207,14 @@ function user_insert($event_name, $data) {
 
 		//* Send the welcome email message
 		$domain = explode('@', $data["new"]["email"])[1];
-		if(file_exists($conf['rootpath'].'/conf-custom/mail/welcome_email_'.$domain.'.txt')) {
+		$html = false;
+		if(file_exists($conf['rootpath'].'/conf-custom/mail/welcome_email_'.$domain.'.html')) {
+			$lines = file($conf['rootpath'].'/conf-custom/mail/welcome_email_'.$domain.'.html');
+			$html = true;
+		} elseif(file_exists($conf['rootpath'].'/conf-custom/mail/welcome_email_'.$conf['language'].'.html')) {
+			$lines = file($conf['rootpath'].'/conf-custom/mail/welcome_email_'.$conf['language'].'.html');
+			$html = true;
+		} elseif(file_exists($conf['rootpath'].'/conf-custom/mail/welcome_email_'.$domain.'.txt')) {
 			$lines = file($conf['rootpath'].'/conf-custom/mail/welcome_email_'.$domain.'.txt');
 		} elseif(file_exists($conf['rootpath'].'/conf-custom/mail/welcome_email_'.$conf['language'].'.txt')) {
 			$lines = file($conf['rootpath'].'/conf-custom/mail/welcome_email_'.$conf['language'].'.txt');
@@ -236,8 +243,13 @@ function user_insert($event_name, $data) {
 		unset($tmp);
 
 		$mailHeaders      = "MIME-Version: 1.0" . "\n";
-		$mailHeaders     .= "Content-type: text/plain; charset=utf-8" . "\n";
-		$mailHeaders     .= "Content-Transfer-Encoding: 8bit" . "\n";
+		if($html) {
+			$mailHeaders     .= "Content-Type: text/html; charset=utf-8" . "\n";
+			$mailHeaders     .= "Content-Transfer-Encoding: quoted-printable" . "\n";
+		} else {
+			$mailHeaders     .= "Content-Type: text/plain; charset=utf-8" . "\n";
+			$mailHeaders     .= "Content-Transfer-Encoding: 8bit" . "\n";
+		}
 		$mailHeaders     .= "From: $welcome_mail_from" . "\n";
 		$mailHeaders     .= "Reply-To: $welcome_mail_from" . "\n";
 		$mailTarget       = $data["new"]["email"];