diff --git a/composer.json b/composer.json
index 799f23a..e57feed 100644
--- a/composer.json
+++ b/composer.json
@@ -7,7 +7,7 @@
         "guzzlehttp/guzzle": "^6.5",
         "spomky-labs/otphp": "^8.3",
         "endroid/qr-code": "^3.2",
-        "phpmailer/phpmailer": "^5.2",
+        "phpmailer/phpmailer": "^6.5",
         "christian-riesen/base32": "^1.3",
         "mibe/feedwriter": "^1.1"
     },
diff --git a/composer.lock b/composer.lock
index 0c401a8..cd24990 100644
--- a/composer.lock
+++ b/composer.lock
@@ -1,10 +1,10 @@
 {
     "_readme": [
         "This file locks the dependencies of your project to a known state",
-        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "090ed2375439b7896af13a7637520a25",
+    "content-hash": "d47f7a78ad560552f73991a0dad9fb28",
     "packages": [
         {
             "name": "bacon/bacon-qr-code",
@@ -821,60 +821,49 @@
         },
         {
             "name": "phpmailer/phpmailer",
-            "version": "v5.2.28",
+            "version": "v6.5.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/PHPMailer/PHPMailer.git",
-                "reference": "acba50393dd03da69a50226c139722af8b153b11"
+                "reference": "a5b5c43e50b7fba655f793ad27303cd74c57363c"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/PHPMailer/PHPMailer/zipball/acba50393dd03da69a50226c139722af8b153b11",
-                "reference": "acba50393dd03da69a50226c139722af8b153b11",
+                "url": "https://api.github.com/repos/PHPMailer/PHPMailer/zipball/a5b5c43e50b7fba655f793ad27303cd74c57363c",
+                "reference": "a5b5c43e50b7fba655f793ad27303cd74c57363c",
                 "shasum": ""
             },
             "require": {
                 "ext-ctype": "*",
-                "php": ">=5.0.0"
+                "ext-filter": "*",
+                "ext-hash": "*",
+                "php": ">=5.5.0"
             },
             "require-dev": {
-                "doctrine/annotations": "1.2.*",
-                "jms/serializer": "0.16.*",
-                "phpdocumentor/phpdocumentor": "2.*",
-                "phpunit/phpunit": "4.8.*",
-                "symfony/debug": "2.8.*",
-                "symfony/filesystem": "2.8.*",
-                "symfony/translation": "2.8.*",
-                "symfony/yaml": "2.8.*",
-                "zendframework/zend-cache": "2.5.1",
-                "zendframework/zend-config": "2.5.1",
-                "zendframework/zend-eventmanager": "2.5.1",
-                "zendframework/zend-filter": "2.5.1",
-                "zendframework/zend-i18n": "2.5.1",
-                "zendframework/zend-json": "2.5.1",
-                "zendframework/zend-math": "2.5.1",
-                "zendframework/zend-serializer": "2.5.*",
-                "zendframework/zend-servicemanager": "2.5.*",
-                "zendframework/zend-stdlib": "2.5.1"
+                "dealerdirect/phpcodesniffer-composer-installer": "^0.7.0",
+                "doctrine/annotations": "^1.2",
+                "phpcompatibility/php-compatibility": "^9.3.5",
+                "roave/security-advisories": "dev-latest",
+                "squizlabs/php_codesniffer": "^3.5.6",
+                "yoast/phpunit-polyfills": "^0.2.0"
             },
             "suggest": {
-                "league/oauth2-google": "Needed for Google XOAUTH2 authentication"
+                "ext-mbstring": "Needed to send email in multibyte encoding charset or decode encoded addresses",
+                "hayageek/oauth2-yahoo": "Needed for Yahoo XOAUTH2 authentication",
+                "league/oauth2-google": "Needed for Google XOAUTH2 authentication",
+                "psr/log": "For optional PSR-3 debug logging",
+                "stevenmaguire/oauth2-microsoft": "Needed for Microsoft XOAUTH2 authentication",
+                "symfony/polyfill-mbstring": "To support UTF-8 if the Mbstring PHP extension is not enabled (^1.2)"
             },
             "type": "library",
             "autoload": {
-                "classmap": [
-                    "class.phpmailer.php",
-                    "class.phpmaileroauth.php",
-                    "class.phpmaileroauthgoogle.php",
-                    "class.smtp.php",
-                    "class.pop3.php",
-                    "extras/EasyPeasyICS.php",
-                    "extras/ntlm_sasl_client.php"
-                ]
+                "psr-4": {
+                    "PHPMailer\\PHPMailer\\": "src/"
+                }
             },
             "notification-url": "https://packagist.org/downloads/",
             "license": [
-                "LGPL-2.1"
+                "LGPL-2.1-only"
             ],
             "authors": [
                 {
@@ -894,7 +883,17 @@
                 }
             ],
             "description": "PHPMailer is a full-featured email creation and transfer class for PHP",
-            "time": "2020-03-19T14:29:37+00:00"
+            "support": {
+                "issues": "https://github.com/PHPMailer/PHPMailer/issues",
+                "source": "https://github.com/PHPMailer/PHPMailer/tree/v6.5.0"
+            },
+            "funding": [
+                {
+                    "url": "https://github.com/Synchro",
+                    "type": "github"
+                }
+            ],
+            "time": "2021-06-16T14:33:43+00:00"
         },
         {
             "name": "psr/http-message",
@@ -1579,5 +1578,6 @@
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": [],
-    "platform-dev": []
+    "platform-dev": [],
+    "plugin-api-version": "2.1.0"
 }