diff --git a/appinfo/info.xml b/appinfo/info.xml
index e24e90e1610da3811244550aa12ca9b2515be969..bb516447788802e3b6b5ed39307916b348296088 100644
--- a/appinfo/info.xml
+++ b/appinfo/info.xml
@@ -5,7 +5,7 @@
 	<name>Email Recovery</name>
 	<summary>Email Recovery App</summary>
 	<description><![CDATA[Email Recovery App]]></description>
-	<version>11.0.1</version>
+	<version>11.0.2</version>
 	<licence>agpl</licence>
 	<author mail="dev@murena.com" homepage="https://murena.com/">MURENA SAS</author>
 	<namespace>EmailRecovery</namespace>
diff --git a/lib/Db/ConfigMapper.php b/lib/Db/ConfigMapper.php
index b7f3484064392ccc0b3a90126127dd2757a7cffb..3248d7c062718601bb12abfdf17feaa3a1e041e6 100644
--- a/lib/Db/ConfigMapper.php
+++ b/lib/Db/ConfigMapper.php
@@ -14,20 +14,33 @@ class ConfigMapper {
 		$this->appName = $appName;
 	}
 
-
-	public function getUsersByRecoveryEmail(string $pattern) : array {
+	private function countRecoveryEmailEntry(string $pattern, string $operation): int {
 		$pattern = strtolower($pattern);
 		$qb = $this->connection->getQueryBuilder();
-		$qb->select('userid')
-			->from("preferences")->where('LOWER(`configvalue`) like :pattern AND (`configkey` = "unverified-recovery-email" OR `configkey` = "recovery-email") AND `appid` = :appname ')
+		$qb->select($qb->func()->count('userid'))
+			->from("preferences")->where("LOWER(`configvalue`) $operation :pattern AND (`configkey` = 'unverified-recovery-email' OR `configkey` = 'recovery-email') AND `appid` = :appname ")
 			->setParameter('pattern', $pattern)
 			->setParameter('appname', $this->appName);
-		$result = $qb->execute();
-		$userIDs = [];
-		while ($row = $result->fetch()) {
-			$userIDs[] = $row['userid'];
+
+		$result = $qb->executeQuery();
+		$count = $result->fetchOne();
+		$result->closeCursor();
+
+		if ($count !== false) {
+			$count = (int)$count;
+		} else {
+			$count = 0;
 		}
-		return $userIDs;
+
+		return $count;
+	}
+
+	public function countRecoveryEmail(string $pattern): int {
+		return $this->countRecoveryEmailEntry($pattern, "like");
+	}
+
+	public function countRecoveryEmailByRegex(string $pattern): int {
+		return $this->countRecoveryEmailEntry($pattern, "REGEXP");
 	}
 
 	public function getAllVerifiedRecoveryEmails(): array {
diff --git a/lib/Service/RecoveryEmailService.php b/lib/Service/RecoveryEmailService.php
index 69a7e376a7cc44488a8a3aa823d6b74c8f4223f3..e213545ac906d9d100b231429a4b83ccf5dcfd41 100644
--- a/lib/Service/RecoveryEmailService.php
+++ b/lib/Service/RecoveryEmailService.php
@@ -52,6 +52,12 @@ class RecoveryEmailService {
 	private const RATE_LIMIT_DOMAIN = 'verifymail_domain_ratelimit';
 	private const RECOVERY_EMAIL_REMINDER_START_DATE = 'recovery-email-reminder-start-date';
 	private const UNVERIFIED_USER_DISABLE_AT = 'unverified-user-disabled-at';
+	private const GMAIL_QUERY_LAST_PART = "(@gmail.com|@googlemail.com)"; //regex: is the str ends with any gmail's domains
+	private const GMAIL_QUERY_MIDDLE_PART = "\+[^@]+"; //regex: for alias email addresses, ignore anything after +
+	private const GMAIL_DOMAINS = [
+		'gmail.com',
+		'googlemail.com',
+	];
 
 	private $cache;
 
@@ -190,6 +196,11 @@ class RecoveryEmailService {
 			throw new RecoveryEmailAlreadyFoundException($l->t('Recovery email address is already taken.'));
 		}
 
+		if ($this->isGmailRecoveryEmailTaken($username, $recoveryEmail)) {
+			$this->logger->info("User ID $username's requested recovery email (gmail) address is already taken");
+			throw new RecoveryEmailAlreadyFoundException($l->t('Recovery email address is already taken.'));
+		}
+
 		if (!$this->isAliasedRecoveryEmailValid($username, $recoveryEmail)) {
 			$this->logger->info("User ID $username's requested recovery extended email address is already taken");
 			throw new RecoveryEmailAlreadyFoundException($l->t('This email address in invalid, please use another one.'));
@@ -355,11 +366,12 @@ class RecoveryEmailService {
 		return false;
 	}
 
-	private function getUsernameAndDomain(string $email) : ?array {
+	private function getUsernameAndDomain(?string $email) : ?array {
 		if ($email === null || empty($email)) {
 			return null;
 		}
 		$email = strtolower($email);
+		$email = trim($email);
 		$emailParts = explode('@', $email);
 		$mailUsernameParts = explode('+', $emailParts[0]);
 		$mailUsername = $mailUsernameParts[0];
@@ -367,6 +379,87 @@ class RecoveryEmailService {
 		return [$mailUsername, $mailDomain];
 	}
 
+	/*
+	* if the provided recoveryMail is gmail check if this is already taken or not.
+	* return false if the recoveryMail is not gmail / alias mail / not taken
+	*/
+	private function isGmailRecoveryEmailTaken(string $username, string $recoveryEmail): bool {
+		// if alias found in the mail address, ignore for now, it will be handle in the next section of the caller
+		if (str_contains($recoveryEmail, '+')) {
+			return false;
+		}
+
+		$mailPrefix = $this->getGmailUsername($recoveryEmail);
+		// provided recoveryEmail is not gmail.
+		if ($mailPrefix === null) {
+			return false;
+		}
+
+		if ($this->isRecoveryGmailBelongsToUser($username, $mailPrefix)) {
+			return false;
+		}
+
+		$regex = $this->getGmailQueryRegexFirstPart($mailPrefix) . self::GMAIL_QUERY_LAST_PART;
+
+		$recoveryEmailCount = $this->configMapper->countRecoveryEmailByRegex($regex);
+		return $recoveryEmailCount > 0;
+	}
+
+	/**
+	 * if provided user already has same gmail account setup as recoveryEmail / unverifiedRecoveryEmail,
+	 * then we assume that is already passed verification once.
+	 * So no need verfication run again.
+	 */
+	private function isRecoveryGmailBelongsToUser(string $username, string $mailPrefix): bool {
+		$currentRecoveryEmail = $this->getRecoveryEmail($username);
+		$currentUnverifiedRecoveryEmail = $this->getUnverifiedRecoveryEmail($username);
+		$currentRecoveryEmailUserPart = $this->getGmailUsername($currentRecoveryEmail);
+		$currentUnverifiedRecoveryEmailUserPart = $this->getGmailUsername($currentUnverifiedRecoveryEmail);
+
+		// requested recoveryEmail is already set by the current user
+		return (($mailPrefix === $currentRecoveryEmailUserPart) || ($mailPrefix === $currentUnverifiedRecoveryEmailUserPart));
+	}
+
+	/**
+	 * return sanitized mailPrefix if provided mail address is gmail
+	 * gmail doesn't care about (.) in the mail address.
+	 */
+	private function getGmailUsername(?string $email): ?string {
+		$emailParts = $this->getUsernameAndDomain($email);
+
+		if ($emailParts == null || !in_array($emailParts[1], self::GMAIL_DOMAINS)) {
+			return null;
+		}
+
+		return str_replace(".", "", $emailParts[0]);
+	}
+
+	/**
+	 * gmail doesn't care about (.) in the mail address.
+	 * So, to retrieve all possible entries using regex from Database, we need to modify the mail prefix
+	 * ex: if the mail address is abc@gmail.com, then the mailPrefix is abc. So, this method will return ^a[.]?b[.]?c[.]?
+	 */
+	private function getGmailQueryRegexFirstPart(string $mailPrefix): string {
+		$regex = "^";
+
+		foreach (str_split($mailPrefix) as $c) {
+			$regex = $regex . $c . "[.]?";
+		}
+
+		return $regex;
+	}
+
+	private function isGmailAliasedRecoveryEmailValid(string $username, string $mailPrefix, int $emailAliasLimit): bool {
+		if ($this->isRecoveryGmailBelongsToUser($username, $mailPrefix)) {
+			return true;
+		}
+
+		$regex = $this->getGmailQueryRegexFirstPart($mailPrefix) . self::GMAIL_QUERY_MIDDLE_PART . self::GMAIL_QUERY_LAST_PART;
+
+		$recoveryEmailCount = $this->configMapper->countRecoveryEmailByRegex($regex);
+		return $recoveryEmailCount < $emailAliasLimit;
+	}
+
 	public function isAliasedRecoveryEmailValid(string $username, string $recoveryEmail): bool {
 		if (!str_contains($recoveryEmail, '+')) {
 			return true;
@@ -376,6 +469,12 @@ class RecoveryEmailService {
 		if ($emailAliasLimit === -1) {
 			return true;
 		}
+	
+		$gmailPrefix = $this->getGmailUsername($recoveryEmail);
+		if ($gmailPrefix !== null) {
+			return $this->isGmailAliasedRecoveryEmailValid($username, $gmailPrefix, $emailAliasLimit);
+		}
+
 		$recoveryEmailregex = $recoveryEmailParts[0]."+%@".$recoveryEmailParts[1];
 		$currentRecoveryEmail = $this->getRecoveryEmail($username);
 		$currentUnverifiedRecoveryEmail = $this->getUnverifiedRecoveryEmail($username);
@@ -387,12 +486,8 @@ class RecoveryEmailService {
 			return true;
 		}
 
-		$usersWithEmailRecovery = $this->configMapper->getUsersByRecoveryEmail($recoveryEmailregex);
-		if (count($usersWithEmailRecovery) > $emailAliasLimit) {
-			return false;
-		}
-
-		return true;
+		$recoveryEmailCount = $this->configMapper->countRecoveryEmail($recoveryEmailregex);
+		return $recoveryEmailCount < $emailAliasLimit;
 	}
 
 	public function updateRecoveryEmail(string $username, string $recoveryEmail) : void {