Author Topic: How to Change your mail port (Some ISP Block 25, 26 port)  (Read 5712 times)

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How to Change your mail port (Some ISP Block 25, 26 port)
« on: March 10, 2015, 07:14:55 AM »
Hello Friends
Some ISP s is blocked 25 and 26 port ( i am from Turkiye, Blocked port 25)
solve this issue:
1-  you change your     path: /etc/postfix/

# ==========================================================================
smtp      inet  n       -       n       -       -       smtpd
#  -o content_filter=smtp-amavis:
#  -o receive_override_options=no_address_mappings

TO :
# ==========================================================================
smtp      inet  n       -       n       -       -       smtpd
587     inet  n       -       n       -       -       smtpd
26      inet  n       -       n       -       -       smtpd
#  -o content_filter=smtp-amavis:
#  -o receive_override_options=no_address_mappings

2- add this 587  and 26 ports in  your firewall incoming and outgoing ports
Your CWP panel --->> Security --> CSF Firewall
                                                 after click First Blue button Firewall Configuration
             find ports line and add your ports. if you use ipv6 add your ports there line too.
# Allow incoming TCP ports
TCP_IN = "20,21,2222,25,26,53,80,110,143,443,465,587,993,995,2030,2031,10011,30033"

# Allow outgoing TCP ports
TCP_OUT = "20,21,2222,25,26,53,80,110,113,443,2030,2031,587,993,995,10011,30033"
Note: i am not sure for add both in and out lines, but i use both

and finally you restart your services or restart your server
good luck ;)
« Last Edit: March 10, 2015, 12:05:57 PM by muhittin »
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Re: How to Change your mail port (Some ISP Block 25, 26 port)
« Reply #1 on: April 13, 2015, 04:00:58 AM »
Thank you for share ;)

You can also use iptables or CSF for simply redirect the inbound/outbound connections to that ports to the one you need.  Without touch the config files but the CSF ports obviously. This is the perfect example for you (

About the inbound and outbound decision, you must add both.

Even if you think the port 25 for SMTP is a sending port, is not.
If you wanna send a email from that SMTP server, you must connect to the port 25 then pass the HELO commands and so on... so,

All the ports are usually inbound/outbound even if the service looks like just 1 way.

About smtp(25)/pop3(110) ports, one is the email, the other is the service for the users/accounts. Both of them uses inbound/outbound data.

You login to the pop3 to receive emails, and you connect to same machine at port 25 to connect the smtp port then send them.

Always there are a negotiation, so you must allow both directions.

« Last Edit: April 13, 2015, 04:04:06 AM by erm3nda »
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