i cannot be able to send emails; port 25 is blocked

Posted December 15, 2019 1.1k views
DigitalOcean Accounts

[root@ns1 ~]# telnet 25
telnet: connect to address Connection timed out
Trying 2607:f8b0:400d:c0f::1b…
telnet: connect to address 2607:f8b0:400d:c0f::1b: Network is unreachable

please help

These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.

Submit an Answer
1 answer

Hi @eleetgeeks,

It’s possible you you need to allow outgoing TCP traffic on port 25

iptables -I INPUT -p tcp -m tcp --dport 25 -j ACCEPT

Additionally, you can further read this DigitalOcean article explaining more about Iptables and what they are -


by Mitchell Anicas
Iptables is a software firewall for Linux distributions. This cheat sheet-style guide provides a quick reference to iptables commands that will create firewall rules that are useful in common, everyday scenarios. This includes iptables examples of allowing and blocking various services by port, network interface, and source IP address.