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Telnet from my mac OSx doesn't work while it works from the AWS instances and other networks. I have no local firewalls. Nothing related in /var/log/system

In the below transcript, the telnet hangs at "Trying" I have tried many different addresses across multiple domains.. same result !

Rocky-Balboas-MacBook-Pro:~ rocky$ 
Rocky-Balboas-MacBook-Pro:~ rocky$ dig MX +short
Rocky-Balboas-MacBook-Pro:~ rocky$ telnet 25
Rocky-Balboas-MacBook-Pro:~ rocky$ telnet localhost 80
Connected to localhost.
Escape character is '^]'.
Connection closed by foreign host.
Rocky-Balboas-MacBook-Pro:~ rocky$ 

edit: let the telnet command run and here are the results

telnet: connect to address Operation timed out
Trying 2a00:1450:4013:c01::1a...
telnet: connect to address 2a00:1450:4013:c01::1a: No route to host
telnet: Unable to connect to remote host
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migrated from Oct 16 '12 at 3:43

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Your ISP may be blocking port 25, to prevent their customers from becoming spam zombies. –  Barmar Oct 16 '12 at 0:56
AWESOME !! I had this same problem 2 years back and totally forgot about it :) DO add it as an answer and I'll accept it, sure this will help many others –  Stewie Oct 16 '12 at 1:04

1 Answer 1

up vote 2 down vote accepted

Your ISP most likely blocks port 25. This is a very common anti-spam technique, to deal with customers whose computers have been infected and turns into spam zombies.

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