diff --git a/htdocs/comm/action/index.php b/htdocs/comm/action/index.php
index 39a37074b1d..ce453609e38 100644
--- a/htdocs/comm/action/index.php
+++ b/htdocs/comm/action/index.php
@@ -1061,12 +1061,21 @@ if (count($listofextcals))
                     $event->id = $icalevent['UID'];
                     $event->ref = $event->id;
 
+                    $userId = $userstatic->findUserIdByEmail($namecal);
+                    if (!empty($userId) && $userId > 0)
+                    {
+                        $event->userassigned[$userId] = $userId;
+                        $event->percentage = -1;
+                    }
+                    else {
+                        $event->type_code = "ICALEVENT";
+                    }
+
                     $event->icalname = $namecal;
                     $event->icalcolor = $colorcal;
                     $usertime = 0; // We dont modify date because we want to have date into memory datep and datef stored as GMT date. Compensation will be done during output.
                     $event->datep = $datestart + $usertime;
                     $event->datef = $dateend + $usertime;
-                    $event->type_code = "ICALEVENT";
 
                     if ($icalevent['SUMMARY']) $event->label = $icalevent['SUMMARY'];
                     elseif ($icalevent['DESCRIPTION']) $event->label = dol_nl2br($icalevent['DESCRIPTION'], 1);
diff --git a/htdocs/user/class/user.class.php b/htdocs/user/class/user.class.php
index fdda769c5f4..30300ff7d91 100644
--- a/htdocs/user/class/user.class.php
+++ b/htdocs/user/class/user.class.php
@@ -3236,5 +3236,65 @@ class User extends CommonObject
             $this->errors[] = $this->db->lasterror();
             return -1;
         }
-    }
+	}
+
+	/**
+	 * Cache the SQL results of the function "findUserIdByEmail($email)"
+	 *
+	 * NOTE: findUserIdByEmailCache[...] === -1 means not found in database
+	 *
+	 * @var array
+	 */
+	private $findUserIdByEmailCache;
+
+	/**
+	 * Find a user by the given e-mail and return it's user id when found
+	 *
+	 * NOTE:
+	 * Use AGENDA_DISABLE_EXACT_USER_EMAIL_COMPARE_FOR_EXTERNAL_CALENDAR
+	 * to disable exact e-mail search
+	 *
+	 * @param string	$email	The full e-mail (or a part of a e-mail)
+	 * @return int				<0 = user was not found, >0 = The id of the user
+	 */
+	public function findUserIdByEmail($email)
+	{
+		if ($this->findUserIdByEmailCache[$email])
+		{
+			return $this->findUserIdByEmailCache[$email];
+		}
+
+		$this->findUserIdByEmailCache[$email] = -1;
+
+		global $conf;
+
+		$sql = 'SELECT rowid';
+		$sql .= ' FROM '.MAIN_DB_PREFIX.'user';
+
+		if (!empty($conf->global->AGENDA_DISABLE_EXACT_USER_EMAIL_COMPARE_FOR_EXTERNAL_CALENDAR))
+		{
+			$sql .= ' WHERE email LIKE "%'.$email.'%"';
+		}
+		else {
+			$sql .= ' WHERE email = "'.$email.'"';
+		}
+
+		$sql .= ' LIMIT 1';
+
+		$resql = $this->db->query($sql);
+		if (!$resql)
+		{
+			return -1;
+		}
+
+		$obj = $this->db->fetch_object($resql);
+		if (!$obj)
+		{
+			return -1;
+		}
+
+		$this->findUserIdByEmailCache[$email] = (int) $obj->rowid;
+
+		return $this->findUserIdByEmailCache[$email];
+	}
 }