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nmanousos / email-existence

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false return always #34

Open devbugice opened 6 years ago

devbugice commented 6 years ago

false return with hotmail and gmail

scream314 commented 6 years ago

Hey, please check if you have outbound TCP port 25 open, many providers block it.

kevflynn commented 6 years ago

Hey @scream314 - thanks for the answer. How do I check that? If it's not open, how do I open it?

scream314 commented 6 years ago

@kevflynn First you should find a working mailserver on the internet to test (or if you have one, you coluld of course us that):

# dig mx google.com

; <<>> DiG 9.10.6 <<>> mx google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22222
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;google.com.            IN  MX

;; ANSWER SECTION:
google.com.     599 IN  MX  30 alt2.aspmx.l.google.com.
google.com.     599 IN  MX  10 aspmx.l.google.com.
google.com.     599 IN  MX  20 alt1.aspmx.l.google.com.
google.com.     599 IN  MX  40 alt3.aspmx.l.google.com.
google.com.     599 IN  MX  50 alt4.aspmx.l.google.com.

;; Query time: 78 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Tue Jan 21 09:34:21 GMT 2032
;; MSG SIZE  rcvd: 136

Then use netcat (or telnet or something equivalent) to determine if you can reach its port 25:

# nc -zv aspmx.l.google.com 25
found 0 associations
found 1 connections:
     1: flags=82<CONNECTED,PREFERRED>
    outif en0
    src 127.0.0.1 port 59360
    dst 66.102.1.27 port 25
    rank info not available
    TCP aux info available

Connection to aspmx.l.google.com port 25 [tcp/smtp] succeeded!

If the port is unreachable and it is not blocked by your firewall, then most probably your ISP is blocking it. If this is the case you could either contact them, and ask them to unblock (for example with my ISP I can disable the block by logging in in my ISP account and unticking a checkbox); or you could rent an external server and forward your mail traffic through it (doing so you would have many options, you could either simply redirect outbound port 25 traffic with sshuttle or use mailservers configured as relay hosts and relay your mail traffic through your external server, etc...). But the easiest method is if your ISP simply removes the restriction.

ThibaultJanBeyer commented 5 years ago

Gmail seems to block these ports… So the tool is not really useful?

knoxcard commented 5 years ago

Gmail works for me. Although, outlook.com/hotmail.com always appears to be returning false.

knoxcard commented 5 years ago

You know what would be cool?

If this module would let you know if port 25 is blocked. It should output DNS diagnosis.