add method to check mail existence

src/mail/check_email_existence.py

@@ -0,0 +1,16 @@
+from src.db.mongo_manager import MONGO_STORE_MANAGER
+from src.utils.excel_reader import ExcelHelper
+
+if __name__ == '__main__':
+    excel_reader = ExcelHelper()
+    contacts = excel_reader.read_contacts("/Users/lpan/Desktop/yahoo_aol.xlsx")
+    mail_list = MONGO_STORE_MANAGER.get_destination_emails()
+    print("mail_list size is " + str(len(mail_list)))
+    mail_raw_list =[]
+    for mail_address in mail_list:
+        mail_raw_list.append(mail_address.mail)
+
+    for contact in contacts:
+        if contact.mail not in mail_raw_list:
+            if "gmail" not in contact.mail:
+                print(contact.mail)