Check SSL certificate expiration

import sys
import OpenSSL
import ssl
import datetime
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

class SslCheck:
    def compose_mail(self,alert_text):
        # Compose From,To,Subject header and Body
        fromaddr = 'from address'
        toaddr = 'to address'
        msg = MIMEMultipart()
        msg['From'] = fromaddr
        msg['To'] = toaddr
        msg['Subject'] = 'SSL Expire Alert'
        body = alert_text
        msg.attach(MIMEText(body,'plain'))
        # Connect Your SMTP server.Here i use gmail smtp server.
        server = smtplib.SMTP('smtp.gmail.com',587)
        server.starttls()
        server.login(fromaddr,'password')
        text = msg.as_string()
        server.sendmail(fromaddr,toaddr,text)
        server.quit()
        
    def ssl_expire(self,cert): 
        load_cert = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM,cert)
        expire_date = datetime.datetime.strptime(load_cert.get_notAfter().decode(),'%Y%m%d%H%M%SZ')
        today = datetime.datetime.today()
        delta = expire_date - today
        alert_text = 'Your SSL certificate will expire {} days'.format(delta.days)
        if delta.days <= 90:
            SslCheck.compose_mail(self,alert_text)
        else:
            print(sys.exc_info()[1])
    
    #  ssl certificate expiration check Using website pem  
    def web_pem(self,site,port):
        cert=ssl.get_server_certificate((site,port))
        SslCheck.ssl_expire(self,cert)
    
    #  ssl certificate expiration check Using host pem  
    def host_pem(self,cert):
        SslCheck.ssl_expire(self,cert)
        
sslvalid = SslCheck()
sslvalid.web_pem('www.google.com', 443)
#sslvalid.host_pem('/home/joe/Program/Python/Micheal/cert/cilogon-globus.pem')