Mail - 25,110,143,993,995

SMTP 25

We can run VRFY to enumerate usernames.

telnet $HOST 25
Trying 10.129.229.147...
Connected to 10.129.229.147.
Escape character is '^]'.
VRFY root
220 ubuntu ESMTP Postfix (Ubuntu)
252 2.0.0 root
VRFY test
550 5.1.1 <test>: Recipient address rejected: User unknown in local recipient table

POP3 110

Trying the same thing with POP3

telnet $HOST 110
Trying 10.129.229.147...
Connected to 10.129.229.147.
Escape character is '^]'.
+OK Dovecot (Ubuntu) ready.
USER root
-ERR [AUTH] Plaintext authentication disallowed on non-secure (SSL/TLS) connections.

POP3 995 - enc

Doesnt work.

telnet $HOST 995
Trying 10.129.229.147...
Connected to 10.129.229.147.
Escape character is '^]'.
USER root
Connection closed by foreign host.