diff --git a/composer.json b/composer.json
index 3c41a15e6..d532b977d 100644
--- a/composer.json
+++ b/composer.json
@@ -31,7 +31,7 @@
         "erusev/parsedown" : "^1.7",
         "pimple/pimple" : "3.2.2",
         "psr/log": "~1.0",
-        "swiftmailer/swiftmailer" : "5.4.8",
+        "swiftmailer/swiftmailer" : "6.2.3",
         "symfony/console" : "4.2.12",
         "symfony/event-dispatcher" : "3.4.2",
         "gregwar/captcha": "1.1.8"
diff --git a/composer.lock b/composer.lock
index 82951a81d..dbf24865c 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "63c9bd26f9ac6022b3198eba7bee6059",
+    "content-hash": "b5c833ea7473f37a40d983d60629e95d",
     "packages": [
         {
             "name": "christian-riesen/base32",
@@ -112,6 +112,126 @@
             ],
             "time": "2015-10-08T08:17:59+00:00"
         },
+        {
+            "name": "doctrine/lexer",
+            "version": "1.2.1",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/doctrine/lexer.git",
+                "reference": "e864bbf5904cb8f5bb334f99209b48018522f042"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/doctrine/lexer/zipball/e864bbf5904cb8f5bb334f99209b48018522f042",
+                "reference": "e864bbf5904cb8f5bb334f99209b48018522f042",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.2 || ^8.0"
+            },
+            "require-dev": {
+                "doctrine/coding-standard": "^6.0",
+                "phpstan/phpstan": "^0.11.8",
+                "phpunit/phpunit": "^8.2"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.2.x-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Doctrine\\Common\\Lexer\\": "lib/Doctrine/Common/Lexer"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Guilherme Blanco",
+                    "email": "guilhermeblanco@gmail.com"
+                },
+                {
+                    "name": "Roman Borschel",
+                    "email": "roman@code-factory.org"
+                },
+                {
+                    "name": "Johannes Schmitt",
+                    "email": "schmittjoh@gmail.com"
+                }
+            ],
+            "description": "PHP Doctrine Lexer parser library that can be used in Top-Down, Recursive Descent Parsers.",
+            "homepage": "https://www.doctrine-project.org/projects/lexer.html",
+            "keywords": [
+                "annotations",
+                "docblock",
+                "lexer",
+                "parser",
+                "php"
+            ],
+            "time": "2020-05-25T17:44:05+00:00"
+        },
+        {
+            "name": "egulias/email-validator",
+            "version": "2.1.17",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/egulias/EmailValidator.git",
+                "reference": "ade6887fd9bd74177769645ab5c474824f8a418a"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/egulias/EmailValidator/zipball/ade6887fd9bd74177769645ab5c474824f8a418a",
+                "reference": "ade6887fd9bd74177769645ab5c474824f8a418a",
+                "shasum": ""
+            },
+            "require": {
+                "doctrine/lexer": "^1.0.1",
+                "php": ">=5.5",
+                "symfony/polyfill-intl-idn": "^1.10"
+            },
+            "require-dev": {
+                "dominicsayers/isemail": "^3.0.7",
+                "phpunit/phpunit": "^4.8.36|^7.5.15",
+                "satooshi/php-coveralls": "^1.0.1"
+            },
+            "suggest": {
+                "ext-intl": "PHP Internationalization Libraries are required to use the SpoofChecking validation"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "2.1.x-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Egulias\\EmailValidator\\": "EmailValidator"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Eduardo Gulias Davis"
+                }
+            ],
+            "description": "A library for validating emails against several RFCs",
+            "homepage": "https://github.com/egulias/EmailValidator",
+            "keywords": [
+                "email",
+                "emailvalidation",
+                "emailvalidator",
+                "validation",
+                "validator"
+            ],
+            "time": "2020-02-13T22:36:52+00:00"
+        },
         {
             "name": "eluceo/ical",
             "version": "0.10.1",
@@ -412,29 +532,37 @@
         },
         {
             "name": "swiftmailer/swiftmailer",
-            "version": "v5.4.8",
+            "version": "v6.2.3",
             "source": {
                 "type": "git",
                 "url": "https://github.com/swiftmailer/swiftmailer.git",
-                "reference": "9a06dc570a0367850280eefd3f1dc2da45aef517"
+                "reference": "149cfdf118b169f7840bbe3ef0d4bc795d1780c9"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/swiftmailer/swiftmailer/zipball/9a06dc570a0367850280eefd3f1dc2da45aef517",
-                "reference": "9a06dc570a0367850280eefd3f1dc2da45aef517",
+                "url": "https://api.github.com/repos/swiftmailer/swiftmailer/zipball/149cfdf118b169f7840bbe3ef0d4bc795d1780c9",
+                "reference": "149cfdf118b169f7840bbe3ef0d4bc795d1780c9",
                 "shasum": ""
             },
             "require": {
-                "php": ">=5.3.3"
+                "egulias/email-validator": "~2.0",
+                "php": ">=7.0.0",
+                "symfony/polyfill-iconv": "^1.0",
+                "symfony/polyfill-intl-idn": "^1.10",
+                "symfony/polyfill-mbstring": "^1.0"
             },
             "require-dev": {
                 "mockery/mockery": "~0.9.1",
-                "symfony/phpunit-bridge": "~3.2"
+                "symfony/phpunit-bridge": "^3.4.19|^4.1.8"
+            },
+            "suggest": {
+                "ext-intl": "Needed to support internationalized email addresses",
+                "true/punycode": "Needed to support internationalized email addresses, if ext-intl is not installed"
             },
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "5.4-dev"
+                    "dev-master": "6.2-dev"
                 }
             },
             "autoload": {
@@ -456,13 +584,13 @@
                 }
             ],
             "description": "Swiftmailer, free feature-rich PHP mailer",
-            "homepage": "http://swiftmailer.org",
+            "homepage": "https://swiftmailer.symfony.com",
             "keywords": [
                 "email",
                 "mail",
                 "mailer"
             ],
-            "time": "2017-05-01T15:54:03+00:00"
+            "time": "2019-11-12T09:31:26+00:00"
         },
         {
             "name": "symfony/console",
@@ -719,6 +847,127 @@
             "homepage": "https://symfony.com",
             "time": "2018-04-04T05:07:11+00:00"
         },
+        {
+            "name": "symfony/polyfill-iconv",
+            "version": "v1.17.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/polyfill-iconv.git",
+                "reference": "c4de7601eefbf25f9d47190abe07f79fe0a27424"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/polyfill-iconv/zipball/c4de7601eefbf25f9d47190abe07f79fe0a27424",
+                "reference": "c4de7601eefbf25f9d47190abe07f79fe0a27424",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.3"
+            },
+            "suggest": {
+                "ext-iconv": "For best performance"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.17-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Polyfill\\Iconv\\": ""
+                },
+                "files": [
+                    "bootstrap.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Nicolas Grekas",
+                    "email": "p@tchwork.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony polyfill for the Iconv extension",
+            "homepage": "https://symfony.com",
+            "keywords": [
+                "compatibility",
+                "iconv",
+                "polyfill",
+                "portable",
+                "shim"
+            ],
+            "time": "2020-05-12T16:47:27+00:00"
+        },
+        {
+            "name": "symfony/polyfill-intl-idn",
+            "version": "v1.17.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/polyfill-intl-idn.git",
+                "reference": "3bff59ea7047e925be6b7f2059d60af31bb46d6a"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/polyfill-intl-idn/zipball/3bff59ea7047e925be6b7f2059d60af31bb46d6a",
+                "reference": "3bff59ea7047e925be6b7f2059d60af31bb46d6a",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.3",
+                "symfony/polyfill-mbstring": "^1.3",
+                "symfony/polyfill-php72": "^1.10"
+            },
+            "suggest": {
+                "ext-intl": "For best performance"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.17-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Polyfill\\Intl\\Idn\\": ""
+                },
+                "files": [
+                    "bootstrap.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Laurent Bassin",
+                    "email": "laurent@bassin.info"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony polyfill for intl's idn_to_ascii and idn_to_utf8 functions",
+            "homepage": "https://symfony.com",
+            "keywords": [
+                "compatibility",
+                "idn",
+                "intl",
+                "polyfill",
+                "portable",
+                "shim"
+            ],
+            "time": "2020-05-12T16:47:27+00:00"
+        },
         {
             "name": "symfony/polyfill-mbstring",
             "version": "v1.17.0",
@@ -777,6 +1026,61 @@
                 "shim"
             ],
             "time": "2020-05-12T16:47:27+00:00"
+        },
+        {
+            "name": "symfony/polyfill-php72",
+            "version": "v1.17.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/polyfill-php72.git",
+                "reference": "f048e612a3905f34931127360bdd2def19a5e582"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/polyfill-php72/zipball/f048e612a3905f34931127360bdd2def19a5e582",
+                "reference": "f048e612a3905f34931127360bdd2def19a5e582",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.3"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.17-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Polyfill\\Php72\\": ""
+                },
+                "files": [
+                    "bootstrap.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Nicolas Grekas",
+                    "email": "p@tchwork.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony polyfill backporting some PHP 7.2+ features to lower PHP versions",
+            "homepage": "https://symfony.com",
+            "keywords": [
+                "compatibility",
+                "polyfill",
+                "portable",
+                "shim"
+            ],
+            "time": "2020-05-12T16:47:27+00:00"
         }
     ],
     "packages-dev": [