diff --git a/cmd/authelia/main.go b/cmd/authelia/main.go
index 9b93cc38f..6b740c347 100644
--- a/cmd/authelia/main.go
+++ b/cmd/authelia/main.go
@@ -130,8 +130,9 @@ func main() {
 		},
 	}
 
-	rootCmd.AddCommand(versionCmd, commands.HashPasswordCmd)
-	rootCmd.AddCommand(commands.CertificatesCmd)
+	rootCmd.AddCommand(versionCmd, commands.HashPasswordCmd,
+		commands.ValidateConfigCmd, commands.CertificatesCmd)
+
 	if err := rootCmd.Execute(); err != nil {
 		log.Fatal(err)
 	}
diff --git a/config.template.yml b/config.template.yml
index de79839ab..881c6d6a0 100644
--- a/config.template.yml
+++ b/config.template.yml
@@ -382,10 +382,10 @@ notifier:
     # {title} is replaced by the text from the notifier
     subject: "[Authelia] {title}"
     # This address is used during the startup check to verify the email configuration is correct. It's not important what it is except if your email server only allows local delivery.
-    ## startup_check_address: test@authelia.com
-    ## trusted_cert: ""
-    ## disable_require_tls: false
-    ## disable_verify_cert: false
+    startup_check_address: test@authelia.com
+    trusted_cert: ""
+    disable_require_tls: false
+    disable_verify_cert: false
 
   # Sending an email using a Gmail account is as simple as the next section.
   # You need to create an app password by following: https://support.google.com/accounts/answer/185833?hl=en
diff --git a/docs/configuration/index.md b/docs/configuration/index.md
index 2207d3e38..849c37736 100644
--- a/docs/configuration/index.md
+++ b/docs/configuration/index.md
@@ -14,7 +14,23 @@ When running **Authelia**, you can specify your configuration by passing
 the file path as shown below.
 
     $ authelia --config config.custom.yml
+ 
+ 
+## Validation
+
+Authelia validates the configuration when it starts. This process checks multiple factors including configuration keys
+that don't exist, configuration keys that have changed, the values of the keys are valid, and that a configuration
+key isn't supplied at the same time as a secret for the same configuration option.
+
+You may also optionally validate your configuration against this validation process manually by using the validate-config
+option with the Authelia binary as shown below. Keep in mind if you're using [secrets](./secrets.md) you will have to 
+manually provide these if you don't want to get certain validation errors (specifically requesting you provide one of 
+the secret values). You can choose to ignore them if you know what you're doing. This command is useful prior to 
+upgrading to prevent configuration changes from impacting downtime in an upgrade.
+
+    $ authelia validate-config configuration.yml
     
+   
 ## Duration Notation Format
 
 We have implemented a string based notation for configuration options that take a duration. This section describes its
diff --git a/go.sum b/go.sum
index e2133873e..682a9eee6 100644
--- a/go.sum
+++ b/go.sum
@@ -458,6 +458,7 @@ golang.org/x/sys v0.0.0-20190624142023-c5567b49c5d0 h1:HyfiK1WMnHj5FXFXatD+Qs1A/
 golang.org/x/sys v0.0.0-20190624142023-c5567b49c5d0/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191010194322-b09406accb47 h1:/XfQ9z7ib8eEJX2hdgFTZJ/ntt0swNk5oYBziWeTCvY=
 golang.org/x/sys v0.0.0-20191010194322-b09406accb47/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd h1:xhmwyvizuTgC2qz7ZlMluP20uW+C3Rm0FD/WLDX8884=
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
diff --git a/internal/commands/validate.go b/internal/commands/validate.go
new file mode 100644
index 000000000..73a9c65b9
--- /dev/null
+++ b/internal/commands/validate.go
@@ -0,0 +1,40 @@
+package commands
+
+import (
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"github.com/authelia/authelia/internal/configuration"
+)
+
+// ValidateConfigCmd uses the internal configuration reader to validate the configuration.
+var ValidateConfigCmd = &cobra.Command{
+	Use:   "validate-config [yaml]",
+	Short: "Check a configuration against the internal configuration validation mechanisms.",
+	Run: func(cobraCmd *cobra.Command, args []string) {
+		configPath := args[0]
+		if _, err := os.Stat(configPath); err != nil {
+			log.Fatalf("Error Loading Configuration: %s\n", err)
+		}
+
+		// TODO: Actually use the configuration to validate some providers like Notifier
+		_, errs := configuration.Read(configPath)
+		if len(errs) != 0 {
+			str := "Errors"
+			if len(errs) == 1 {
+				str = "Error"
+			}
+			errors := ""
+			for _, err := range errs {
+				errors += fmt.Sprintf("\t%s\n", err.Error())
+			}
+			log.Fatalf("%s occurred parsing configuration:\n%s", str, errors)
+		} else {
+			log.Println("Configuration parsed successfully without errors.")
+		}
+	},
+	Args: cobra.MinimumNArgs(1),
+}
diff --git a/internal/configuration/reader.go b/internal/configuration/reader.go
index f8c305ae5..f963fe55a 100644
--- a/internal/configuration/reader.go
+++ b/internal/configuration/reader.go
@@ -48,6 +48,7 @@ func Read(configPath string) (*schema.Configuration, []error) {
 	val := schema.NewStructValidator()
 	validator.ValidateSecrets(&configuration, val, viper.GetViper())
 	validator.ValidateConfiguration(&configuration, val)
+	validator.ValidateKeys(val, viper.AllKeys())
 
 	if val.HasErrors() {
 		return nil, val.Errors()
diff --git a/internal/configuration/reader_test.go b/internal/configuration/reader_test.go
index 0bc6cffaa..75a716c48 100644
--- a/internal/configuration/reader_test.go
+++ b/internal/configuration/reader_test.go
@@ -2,6 +2,7 @@ package configuration
 
 import (
 	"os"
+	"sort"
 	"strings"
 	"testing"
 
@@ -29,6 +30,7 @@ func TestShouldParseConfigFile(t *testing.T) {
 	require.NoError(t, os.Setenv("AUTHELIA_NOTIFIER_SMTP_PASSWORD", "smtp_secret_from_env"))
 	require.NoError(t, os.Setenv("AUTHELIA_SESSION_REDIS_PASSWORD", "redis_secret_from_env"))
 	require.NoError(t, os.Setenv("AUTHELIA_STORAGE_MYSQL_PASSWORD", "mysql_secret_from_env"))
+	require.NoError(t, os.Setenv("AUTHELIA_STORAGE_POSTGRES_PASSWORD", "postgres_secret_from_env"))
 
 	config, errors := Read("./test_resources/config.yml")
 
@@ -73,6 +75,33 @@ func TestShouldParseAltConfigFile(t *testing.T) {
 	assert.Len(t, config.AccessControl.Rules, 12)
 }
 
+func TestShouldNotParseConfigFileWithOldOrUnexpectedKeys(t *testing.T) {
+	require.NoError(t, os.Setenv("AUTHELIA_JWT_SECRET", "secret_from_env"))
+	require.NoError(t, os.Setenv("AUTHELIA_DUO_API_SECRET_KEY", "duo_secret_from_env"))
+	require.NoError(t, os.Setenv("AUTHELIA_SESSION_SECRET", "session_secret_from_env"))
+	require.NoError(t, os.Setenv("AUTHELIA_AUTHENTICATION_BACKEND_LDAP_PASSWORD", "ldap_secret_from_env"))
+	require.NoError(t, os.Setenv("AUTHELIA_NOTIFIER_SMTP_PASSWORD", "smtp_secret_from_env"))
+	require.NoError(t, os.Setenv("AUTHELIA_SESSION_REDIS_PASSWORD", "redis_secret_from_env"))
+	require.NoError(t, os.Setenv("AUTHELIA_STORAGE_MYSQL_PASSWORD", "mysql_secret_from_env"))
+	require.NoError(t, os.Setenv("AUTHELIA_STORAGE_POSTGRES_PASSWORD", "postgres_secret_from_env"))
+
+	_, errors := Read("./test_resources/config_bad_keys.yml")
+	require.Len(t, errors, 2)
+
+	// Sort error slice to prevent shenanigans that somehow occur
+	sort.Slice(errors, func(i, j int) bool {
+		return errors[i].Error() < errors[j].Error()
+	})
+	assert.EqualError(t, errors[0], "config key not expected: loggy_file")
+	assert.EqualError(t, errors[1], "config key replaced: logs_level is now log_level")
+}
+
+func TestShouldValidateConfigurationTemplate(t *testing.T) {
+	resetEnv()
+	_, errors := Read("../../config.template.yml")
+	assert.Len(t, errors, 0)
+}
+
 func TestShouldOnlyAllowOneEnvType(t *testing.T) {
 	resetEnv()
 	require.NoError(t, os.Setenv("AUTHELIA_STORAGE_POSTGRES_PASSWORD", "postgres_secret_from_env"))
diff --git a/internal/configuration/test_resources/config_bad_keys.yml b/internal/configuration/test_resources/config_bad_keys.yml
new file mode 100644
index 000000000..8f1b55583
--- /dev/null
+++ b/internal/configuration/test_resources/config_bad_keys.yml
@@ -0,0 +1,124 @@
+###############################################################
+#                   Authelia configuration                    #
+###############################################################
+
+host: 127.0.0.1
+port: 9091
+loggy_file: /etc/authelia/svc.log
+
+logs_level: debug
+default_redirection_url: https://home.example.com:8080/
+
+totp:
+  issuer: authelia.com
+
+duo_api:
+  hostname: api-123456789.example.com
+  integration_key: ABCDEF
+
+authentication_backend:
+  ldap:
+    url: ldap://127.0.0.1
+    base_dn: dc=example,dc=com
+    username_attribute: uid
+    additional_users_dn: ou=users
+    users_filter: (&({username_attribute}={input})(objectCategory=person)(objectClass=user))
+    additional_groups_dn: ou=groups
+    groups_filter: (&(member={dn})(objectclass=groupOfNames))
+    group_name_attribute: cn
+    mail_attribute: mail
+    user: cn=admin,dc=example,dc=com
+
+access_control:
+  default_policy: deny
+
+  rules:
+    # Rules applied to everyone
+    - domain: public.example.com
+      policy: bypass
+
+    - domain: secure.example.com
+      policy: one_factor
+      # Network based rule, if not provided any network matches.
+      networks:
+        - 192.168.1.0/24
+    - domain: secure.example.com
+      policy: two_factor
+
+    - domain: [singlefactor.example.com, onefactor.example.com]
+      policy: one_factor
+
+    # Rules applied to 'admins' group
+    - domain: "mx2.mail.example.com"
+      subject: "group:admins"
+      policy: deny
+    - domain: "*.example.com"
+      subject: "group:admins"
+      policy: two_factor
+
+    # Rules applied to 'dev' group
+    - domain: dev.example.com
+      resources:
+        - "^/groups/dev/.*$"
+      subject: "group:dev"
+      policy: two_factor
+
+    # Rules applied to user 'john'
+    - domain: dev.example.com
+      resources:
+        - "^/users/john/.*$"
+      subject: "user:john"
+      policy: two_factor
+
+    # Rules applied to 'dev' group and user 'john'
+    - domain: dev.example.com
+      resources:
+        - "^/deny-all.*$"
+      subject: ["group:dev", "user:john"]
+      policy: denied
+
+    # Rules applied to user 'harry'
+    - domain: dev.example.com
+      resources:
+        - "^/users/harry/.*$"
+      subject: "user:harry"
+      policy: two_factor
+
+    # Rules applied to user 'bob'
+    - domain: "*.mail.example.com"
+      subject: "user:bob"
+      policy: two_factor
+    - domain: "dev.example.com"
+      resources:
+        - "^/users/bob/.*$"
+      subject: "user:bob"
+      policy: two_factor
+
+session:
+  name: authelia_session
+  expiration: 3600000 # 1 hour
+  inactivity: 300000 # 5 minutes
+  domain: example.com
+  redis:
+    host: 127.0.0.1
+    port: 6379
+
+regulation:
+  max_retries: 3
+  find_time: 120
+  ban_time: 300
+
+storage:
+  mysql:
+    host: 127.0.0.1
+    port: 3306
+    database: authelia
+    username: authelia
+
+notifier:
+  smtp:
+    username: test
+    host: 127.0.0.1
+    port: 1025
+    sender: admin@example.com
+    disable_require_tls: true
\ No newline at end of file
diff --git a/internal/configuration/validator/const.go b/internal/configuration/validator/const.go
new file mode 100644
index 000000000..70f6d3412
--- /dev/null
+++ b/internal/configuration/validator/const.go
@@ -0,0 +1,148 @@
+package validator
+
+var validKeys = []string{
+	// Root Keys.
+	"host",
+	"port",
+	"log_level",
+	"log_file_path",
+	"default_redirection_url",
+	"jwt_secret",
+	"tls_key",
+	"tls_cert",
+	"google_analytics",
+
+	// TOTP Keys
+	"totp.issuer",
+	"totp.period",
+	"totp.skew",
+
+	// Access Control Keys
+	"access_control.rules",
+	"access_control.default_policy",
+
+	// Session Keys.
+	"session.name",
+	"session.secret",
+	"session.expiration",
+	"session.inactivity",
+	"session.remember_me_duration",
+	"session.domain",
+
+	// Redis Session Keys.
+	"session.redis.host",
+	"session.redis.port",
+	"session.redis.password",
+	"session.redis.database_index",
+
+	// Local Storage Keys.
+	"storage.local.path",
+
+	// MySQL Storage Keys.
+	"storage.mysql.host",
+	"storage.mysql.port",
+	"storage.mysql.database",
+	"storage.mysql.username",
+	"storage.mysql.password",
+
+	// PostgreSQL Storage Keys.
+	"storage.postgres.host",
+	"storage.postgres.port",
+	"storage.postgres.database",
+	"storage.postgres.username",
+	"storage.postgres.password",
+	"storage.postgres.sslmode",
+
+	// FileSystem Notifier Keys.
+	"notifier.filesystem.filename",
+	"notifier.disable_startup_check",
+
+	// SMTP Notifier Keys.
+	"notifier.smtp.username",
+	"notifier.smtp.password",
+	"notifier.smtp.host",
+	"notifier.smtp.port",
+	"notifier.smtp.sender",
+	"notifier.smtp.subject",
+	"notifier.smtp.startup_check_address",
+	"notifier.smtp.disable_require_tls",
+	"notifier.smtp.disable_verify_cert",
+	"notifier.smtp.trusted_cert",
+
+	// Regulation Keys.
+	"regulation.max_retries",
+	"regulation.find_time",
+	"regulation.ban_time",
+
+	// DUO API Keys.
+	"duo_api.hostname",
+	"duo_api.integration_key",
+	"duo_api.secret_key",
+
+	// Authentication Backend Keys.
+	"authentication_backend.disable_reset_password",
+
+	// LDAP Authentication Backend Keys.
+	"authentication_backend.ldap.url",
+	"authentication_backend.ldap.skip_verify",
+	"authentication_backend.ldap.base_dn",
+	"authentication_backend.ldap.username_attribute",
+	"authentication_backend.ldap.additional_users_dn",
+	"authentication_backend.ldap.users_filter",
+	"authentication_backend.ldap.additional_groups_dn",
+	"authentication_backend.ldap.groups_filter",
+	"authentication_backend.ldap.group_name_attribute",
+	"authentication_backend.ldap.mail_attribute",
+	"authentication_backend.ldap.user",
+	"authentication_backend.ldap.password",
+
+	// File Authentication Backend Keys.
+	"authentication_backend.file.path",
+	"authentication_backend.file.password.algorithm",
+	"authentication_backend.file.password.iterations",
+	"authentication_backend.file.password.key_length",
+	"authentication_backend.file.password.salt_length",
+	"authentication_backend.file.password.memory",
+	"authentication_backend.file.password.parallelism",
+
+	// Secret Keys.
+	"authelia.jwt_secret",
+	"authelia.duo_api.secret_key",
+	"authelia.session.secret",
+	"authelia.authentication_backend.ldap.password",
+	"authelia.notifier.smtp.password",
+	"authelia.session.redis.password",
+	"authelia.storage.mysql.password",
+	"authelia.storage.postgres.password",
+	"authelia.jwt_secret.file",
+	"authelia.duo_api.secret_key.file",
+	"authelia.session.secret.file",
+	"authelia.authentication_backend.ldap.password.file",
+	"authelia.notifier.smtp.password.file",
+	"authelia.session.redis.password.file",
+	"authelia.storage.mysql.password.file",
+	"authelia.storage.postgres.password.file",
+}
+
+var specificErrorKeys = map[string]string{
+	"logs_file_path": "config key replaced: logs_file is now log_file",
+	"logs_level":     "config key replaced: logs_level is now log_level",
+	"authentication_backend.file.password_options.algorithm":   "config key incorrect: authentication_backend.file.password_options should be authentication_backend.file.password",
+	"authentication_backend.file.password_options.iterations":  "config key incorrect: authentication_backend.file.password_options should be authentication_backend.file.password",
+	"authentication_backend.file.password_options.key_length":  "config key incorrect: authentication_backend.file.password_options should be authentication_backend.file.password",
+	"authentication_backend.file.password_options.salt_length": "config key incorrect: authentication_backend.file.password_options should be authentication_backend.file.password",
+	"authentication_backend.file.password_options.memory":      "config key incorrect: authentication_backend.file.password_options should be authentication_backend.file.password",
+	"authentication_backend.file.password_options.parallelism": "config key incorrect: authentication_backend.file.password_options should be authentication_backend.file.password",
+	"authentication_backend.file.password_hashing.algorithm":   "config key incorrect: authentication_backend.file.password_hashing should be authentication_backend.file.password",
+	"authentication_backend.file.password_hashing.iterations":  "config key incorrect: authentication_backend.file.password_hashing should be authentication_backend.file.password",
+	"authentication_backend.file.password_hashing.key_length":  "config key incorrect: authentication_backend.file.password_hashing should be authentication_backend.file.password",
+	"authentication_backend.file.password_hashing.salt_length": "config key incorrect: authentication_backend.file.password_hashing should be authentication_backend.file.password",
+	"authentication_backend.file.password_hashing.memory":      "config key incorrect: authentication_backend.file.password_hashing should be authentication_backend.file.password",
+	"authentication_backend.file.password_hashing.parallelism": "config key incorrect: authentication_backend.file.password_hashing should be authentication_backend.file.password",
+	"authentication_backend.file.hashing.algorithm":            "config key incorrect: authentication_backend.file.hashing should be authentication_backend.file.password",
+	"authentication_backend.file.hashing.iterations":           "config key incorrect: authentication_backend.file.hashing should be authentication_backend.file.password",
+	"authentication_backend.file.hashing.key_length":           "config key incorrect: authentication_backend.file.hashing should be authentication_backend.file.password",
+	"authentication_backend.file.hashing.salt_length":          "config key incorrect: authentication_backend.file.hashing should be authentication_backend.file.password",
+	"authentication_backend.file.hashing.memory":               "config key incorrect: authentication_backend.file.hashing should be authentication_backend.file.password",
+	"authentication_backend.file.hashing.parallelism":          "config key incorrect: authentication_backend.file.hashing should be authentication_backend.file.password",
+}
diff --git a/internal/configuration/validator/keys.go b/internal/configuration/validator/keys.go
new file mode 100644
index 000000000..6d07b7cbc
--- /dev/null
+++ b/internal/configuration/validator/keys.go
@@ -0,0 +1,29 @@
+package validator
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/authelia/authelia/internal/configuration/schema"
+	"github.com/authelia/authelia/internal/utils"
+)
+
+func ValidateKeys(validator *schema.StructValidator, keys []string) {
+	var errStrings []string
+	for _, key := range keys {
+		if utils.IsStringInSlice(key, validKeys) {
+			continue
+		}
+
+		if err, ok := specificErrorKeys[key]; ok {
+			if !utils.IsStringInSlice(err, errStrings) {
+				errStrings = append(errStrings, err)
+			}
+		} else {
+			validator.Push(fmt.Errorf("config key not expected: %s", key))
+		}
+	}
+	for _, err := range errStrings {
+		validator.Push(errors.New(err))
+	}
+}
diff --git a/internal/configuration/validator/keys_test.go b/internal/configuration/validator/keys_test.go
new file mode 100644
index 000000000..d5b156ce6
--- /dev/null
+++ b/internal/configuration/validator/keys_test.go
@@ -0,0 +1,83 @@
+package validator
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/authelia/authelia/internal/configuration/schema"
+	"github.com/authelia/authelia/internal/utils"
+)
+
+func TestShouldValidateGoodKeys(t *testing.T) {
+	configKeys := validKeys
+	val := schema.NewStructValidator()
+	ValidateKeys(val, configKeys)
+
+	require.Len(t, val.Errors(), 0)
+}
+
+func TestShouldNotValidateBadKeys(t *testing.T) {
+	configKeys := validKeys
+	configKeys = append(configKeys, "bad_key")
+	configKeys = append(configKeys, "totp.skewy")
+	val := schema.NewStructValidator()
+	ValidateKeys(val, configKeys)
+
+	errs := val.Errors()
+	require.Len(t, errs, 2)
+
+	assert.EqualError(t, errs[0], "config key not expected: bad_key")
+	assert.EqualError(t, errs[1], "config key not expected: totp.skewy")
+}
+
+func TestAllSpecificErrorKeys(t *testing.T) {
+	var configKeys []string //nolint:prealloc // This is because the test is dynamic based on the keys that exist in the map
+	var uniqueValues []string
+
+	// Setup configKeys and uniqueValues expected.
+	for key, value := range specificErrorKeys {
+		configKeys = append(configKeys, key)
+		if !utils.IsStringInSlice(value, uniqueValues) {
+			uniqueValues = append(uniqueValues, value)
+		}
+	}
+
+	val := schema.NewStructValidator()
+	ValidateKeys(val, configKeys)
+
+	errs := val.Errors()
+
+	// Check only unique errors are shown. Require because if we don't the next test panics.
+	require.Len(t, errs, len(uniqueValues))
+
+	// Dynamically check all specific errors.
+	for i, value := range uniqueValues {
+		assert.EqualError(t, errs[i], value)
+	}
+}
+
+func TestSpecificErrorKeys(t *testing.T) {
+	configKeys := []string{
+		"logs_level",
+		"logs_file_path",
+		"authentication_backend.file.password_options.algorithm",
+		"authentication_backend.file.password_options.iterations", // This should not show another error since our target for the specific error is password_options.
+		"authentication_backend.file.password_hashing.algorithm",
+		"authentication_backend.file.hashing.algorithm",
+	}
+
+	val := schema.NewStructValidator()
+	ValidateKeys(val, configKeys)
+
+	errs := val.Errors()
+
+	require.Len(t, errs, 5)
+
+	assert.EqualError(t, errs[0], specificErrorKeys["logs_level"])
+	assert.EqualError(t, errs[1], specificErrorKeys["logs_file_path"])
+	assert.EqualError(t, errs[2], specificErrorKeys["authentication_backend.file.password_options.iterations"])
+	assert.EqualError(t, errs[3], specificErrorKeys["authentication_backend.file.password_hashing.algorithm"])
+	assert.EqualError(t, errs[4], specificErrorKeys["authentication_backend.file.hashing.algorithm"])
+}