Fake email domain crawler

gistfile1.txt

#!/usr/bin/env python3
""" Fake email domain crawler
uses search page of known temp mail provider to crawl domains
These domains are getting used on, among others: 
https://generator.email/
https://emailfake.com/
https://email-fake.com/
1.) slowly retrives results for strings aaa-zzz, validates DNS and stores in set
2.) fetches public tld list from icann
3.) writes entry with one "." and known tld into outfile
"""

import requests
import dns.resolver

from string import ascii_lowercase
from time import sleep


baseurl = "https://generator.email/search.php?key="
tld_list = "https://data.iana.org/TLD/tlds-alpha-by-domain.txt"
output = "./domains.lst"

domains = set()

def generator_silables():
    for c in ascii_lowercase:
        for a in ascii_lowercase:
            for r in ascii_lowercase:
                yield c+a+r

def tld_array():
    t = requests.get(tld_list)
    return [ i.lower() for i in t.text.split("\n")[1:-1] ]

def has_mx(domain):
    try:
        records = dns.resolver.resolve(domain, 'MX', raise_on_no_answer=False) 
        if len(records) > 0:
            return True
    except dns.resolver.NXDOMAIN:
        pass
    except dns.exception.Timeout:
        pass

    print("%s is invalid, filtered" % domain)
    return False

try:
    #for i in ["ook", "rub", "aaa", "duc", "all"]:
    for i in generator_silables():
        response = requests.get(baseurl + i)
        if response.status_code == 200:
            print("%s - %s" % (i, str(response.json())))
            for r in response.json():
                if has_mx(r):
                    domains.update([r])
            
except Exception as e:
    print(e)
    print(domains)

tlds = tld_array()
outfile = open(output, "w")
try:
    for j in domains:
        if j.count(".") == 1 and j.split(".")[-1] in tlds:
            outfile.write(j+"\n")
finally:
    print("Done writing '%s'" % output)
    outfile.close()