Nálam ez így néz ki:
pi@raspizerow:~ $ telnet smtp.upcmail.hu 25
Trying 213.46.255.39...
Connected to smtp.upcmail.hu.
Escape character is '^]'.
220 vie01a-pemc-psmtp-pe12.mail.upcmail.net vie01a-pemc-psmtp-pe12.mail.upcmail.net ESMTP server ready
quit
221 2.0.0 vie01a-pemc-psmtp-pe12.mail.upcmail.net vie01a-pemc-psmtp-pe12.mail.upcmail.net closing connection
Connection closed by foreign host.
pi@raspizerow:~ $ telnet smtp.gmail.com 25
Trying 74.125.140.108...
Trying 2a00:1450:400c:c08::6d...
telnet: Unable to connect to remote host: Network is unreachable
pi@raspizerow:~ $ telnet smtp.google.com 25
Trying 74.125.133.26...
Trying 64.233.167.27...
Trying 74.125.71.27...
Trying 64.233.167.26...
Trying 74.125.206.27...
Trying 2a00:1450:400c:c07::1a...
Trying 2a00:1450:400c:c07::1b...
Trying 2a00:1450:400c:c0a::1b...
Trying 2a00:1450:400c:c02::1b...
telnet: Unable to connect to remote host: Network is unreachable
pi@raspizerow:~ $Én is helyi problémára gyanakszom, de végfelhasználóként esélyem sincs olyan emberrel beszélni aki 1. Érti miről beszélek, 2. Hisz nekem, 3. Tenni is tud valamit