diff --git a/app/meteor-accounts-saml/server/saml_rocketchat.js b/app/meteor-accounts-saml/server/saml_rocketchat.js
index 2ee0e2fe05643..b69f33cbe3514 100644
--- a/app/meteor-accounts-saml/server/saml_rocketchat.js
+++ b/app/meteor-accounts-saml/server/saml_rocketchat.js
@@ -85,12 +85,44 @@ Meteor.methods({
 			section: name,
 			i18nLabel: 'Accounts_OAuth_Custom_Button_Color',
 		});
+		settings.add(`SAML_Custom_${ name }_email_field`, 'email', {
+			type: 'string',
+			group: 'SAML',
+			section: name,
+			i18nLabel: 'SAML_Custom_EMail_Field',
+		});
+		settings.add(`SAML_Custom_${ name }_username_field`, 'username', {
+			type: 'string',
+			group: 'SAML',
+			section: name,
+			i18nLabel: 'SAML_Custom_Username_Field',
+		});
 		settings.add(`SAML_Custom_${ name }_generate_username`, false, {
 			type: 'boolean',
 			group: 'SAML',
 			section: name,
 			i18nLabel: 'SAML_Custom_Generate_Username',
 		});
+		settings.add(`SAML_Custom_${ name }_username_normalize`, 'None', {
+			type: 'select',
+			values: [
+				{ key: 'None', i18nLabel: 'SAML_Custom_Username_Normalize_None' },
+				{ key: 'Lowercase', i18nLabel: 'SAML_Custom_Username_Normalize_Lowercase' },
+			],
+			group: 'SAML',
+			section: name,
+			i18nLabel: 'SAML_Custom_Username_Normalize',
+		});
+		settings.add(`SAML_Custom_${ name }_immutable_property`, 'EMail', {
+			type: 'select',
+			values: [
+				{ key: 'Username', i18nLabel: 'SAML_Custom_Immutable_Property_Username' },
+				{ key: 'EMail', i18nLabel: 'SAML_Custom_Immutable_Property_EMail' },
+			],
+			group: 'SAML',
+			section: name,
+			i18nLabel: 'SAML_Custom_Immutable_Property',
+		});
 		settings.add(`SAML_Custom_${ name }_debug`, false, {
 			type: 'boolean',
 			group: 'SAML',
@@ -140,6 +172,10 @@ const getSamlConfigs = function(service) {
 		},
 		entryPoint: settings.get(`${ service.key }_entry_point`),
 		idpSLORedirectURL: settings.get(`${ service.key }_idp_slo_redirect_url`),
+		usernameField: settings.get(`${ service.key }_username_field`),
+		usernameNormalize: settings.get(`${ service.key }_username_normalize`),
+		emailField: settings.get(`${ service.key }_email_field`),
+		immutableProperty: settings.get(`${ service.key }_immutable_property`),
 		generateUsername: settings.get(`${ service.key }_generate_username`),
 		debug: settings.get(`${ service.key }_debug`),
 		nameOverwrite    : settings.get(`${ service.key }_name_overwrite`),
@@ -179,6 +215,10 @@ const configureSamlService = function(samlConfigs) {
 	Accounts.saml.settings.generateUsername = samlConfigs.generateUsername;
 	Accounts.saml.settings.nameOverwrite = samlConfigs.nameOverwrite;
 	Accounts.saml.settings.mailOverwrite = samlConfigs.mailOverwrite;
+	Accounts.saml.settings.immutableProperty = samlConfigs.immutableProperty;
+	Accounts.saml.settings.emailField = samlConfigs.emailField;
+	Accounts.saml.settings.usernameField = samlConfigs.usernameField;
+	Accounts.saml.settings.usernameNormalize = samlConfigs.usernameNormalize;
 	Accounts.saml.settings.debug = samlConfigs.debug;
 
 	return {
diff --git a/app/meteor-accounts-saml/server/saml_server.js b/app/meteor-accounts-saml/server/saml_server.js
index db5699fe334ec..1f192ec1f8397 100644
--- a/app/meteor-accounts-saml/server/saml_server.js
+++ b/app/meteor-accounts-saml/server/saml_server.js
@@ -93,6 +93,16 @@ Meteor.methods({
 	},
 });
 
+Accounts.normalizeUsername = function(name) {
+	switch (Accounts.saml.settings.usernameNormalize) {
+		case 'Lowercase':
+			name = name.toLowerCase();
+			break;
+	}
+
+	return name;
+};
+
 Accounts.registerLoginHandler(function(loginRequest) {
 	if (!loginRequest.saml || !loginRequest.credentialToken) {
 		return undefined;
@@ -110,8 +120,10 @@ Accounts.registerLoginHandler(function(loginRequest) {
 		};
 	}
 
+	const { emailField, usernameField } = Accounts.saml.settings;
+
 	if (loginResult && loginResult.profile && loginResult.profile.email) {
-		const emailList = Array.isArray(loginResult.profile.email) ? loginResult.profile.email : [loginResult.profile.email];
+		const emailList = Array.isArray(loginResult.profile[emailField]) ? loginResult.profile[emailField] : [loginResult.profile[emailField]];
 		const emailRegex = new RegExp(emailList.map((email) => `^${ RegExp.escape(email) }$`).join('|'), 'i');
 
 		const eduPersonPrincipalName = loginResult.profile.eppn;
@@ -128,32 +140,44 @@ Accounts.registerLoginHandler(function(loginRequest) {
 			eppnMatch = true;
 		}
 
+		let username;
+		if (loginResult.profile[usernameField]) {
+			username = Accounts.normalizeUsername(loginResult.profile[usernameField]);
+		}
+
 		// If eppn is not exist
 		if (!user) {
-			user = Meteor.users.findOne({
-				'emails.address': emailRegex,
-			});
+			if (Accounts.saml.settings.immutableProperty === 'Username') {
+				user = Meteor.users.findOne({
+					username,
+				});
+			} else {
+				user = Meteor.users.findOne({
+					'emails.address': emailRegex,
+				});
+			}
 		}
 
+		const emails = emailList.map((email) => ({
+			address: email,
+			verified: true,
+		}));
+
 		if (!user) {
 			const newUser = {
 				name: fullName,
 				active: true,
 				eppn: eduPersonPrincipalName,
 				globalRoles: ['user'],
-				emails: emailList.map((email) => ({
-					address: email,
-					verified: true,
-				})),
+				emails,
 			};
 
 			if (Accounts.saml.settings.generateUsername === true) {
-				const username = generateUsernameSuggestion(newUser);
-				if (username) {
-					newUser.username = username;
-				}
-			} else if (loginResult.profile.username) {
-				newUser.username = loginResult.profile.username;
+				username = generateUsernameSuggestion(newUser);
+			}
+
+			if (username) {
+				newUser.username = username;
 			}
 
 			const userId = Accounts.insertUserDoc({}, newUser);
@@ -192,6 +216,8 @@ Accounts.registerLoginHandler(function(loginRequest) {
 			$set: {
 				// TBD this should be pushed, otherwise we're only able to SSO into a single IDP at a time
 				'services.saml': samlLogin,
+				username,
+				emails,
 			},
 		});
 
diff --git a/packages/rocketchat-i18n/i18n/de.i18n.json b/packages/rocketchat-i18n/i18n/de.i18n.json
index e335b0e63c1ba..9f4aa86edc826 100644
--- a/packages/rocketchat-i18n/i18n/de.i18n.json
+++ b/packages/rocketchat-i18n/i18n/de.i18n.json
@@ -2543,6 +2543,14 @@
   "SAML_Custom_Logout_Behaviour_Terminate_SAML_Session": "SAML-Session beenden",
   "SAML_Custom_Private_Key": "Privater Schlüssel",
   "SAML_Custom_Provider": "Benutzerdefinierter Provider",
+  "SAML_Custom_EMail_Field": "E-Mail Feldname",
+  "SAML_Custom_Username_Field": "Username Feldname",
+  "SAML_Custom_Username_Normalize": "Benutzername normalisierung",
+  "SAML_Custom_Username_Normalize_None": "Keine normalisierung",
+  "SAML_Custom_Username_Normalize_Lowercase": "Zu Kleinschreibung",
+  "SAML_Custom_Immutable_Property": "Unveränderbares Feld",
+  "SAML_Custom_Immutable_Property_Username": "Benutzername",
+  "SAML_Custom_Immutable_Property_EMail": "E-Mail",
   "SAML_Custom_Public_Cert": "Öffentliches Zertifikat",
   "Saturday": "Samstag",
   "Save": "Speichern",
diff --git a/packages/rocketchat-i18n/i18n/en.i18n.json b/packages/rocketchat-i18n/i18n/en.i18n.json
index e4f6eba924157..c10bf609c64aa 100644
--- a/packages/rocketchat-i18n/i18n/en.i18n.json
+++ b/packages/rocketchat-i18n/i18n/en.i18n.json
@@ -2547,6 +2547,14 @@
   "SAML_Custom_Logout_Behaviour_Terminate_SAML_Session": "Terminate SAML-session",
   "SAML_Custom_Private_Key": "Private Key Contents",
   "SAML_Custom_Provider": "Custom Provider",
+  "SAML_Custom_EMail_Field": "E-Mail field name",
+  "SAML_Custom_Username_Field": "Username field name",
+  "SAML_Custom_Username_Normalize": "Normalize username",
+  "SAML_Custom_Username_Normalize_None": "No normalization",
+  "SAML_Custom_Username_Normalize_Lowercase": "To Lowercase",
+  "SAML_Custom_Immutable_Property": "Immutable field name",
+  "SAML_Custom_Immutable_Property_Username": "Username",
+  "SAML_Custom_Immutable_Property_EMail": "E-Mail",
   "SAML_Custom_Public_Cert": "Public Cert Contents",
   "Saturday": "Saturday",
   "Save": "Save",