fatal: parameter inet_interfaces: no local interface found for ::1

Issue:

1. Unable to start postfix service.
2. Unable to send outgoing email.
3. In my case this error came while starting postfix Service.  
4. fatal: parameter inet_interfaces: no local interface found for ::1

What is Postfix?

Postfix is a free MTA used for routing and delivering E-mails. 

Pic credit : wikipedia

Solution:

1. Disable IPv6.
2. Comment the ipv6 entry in /etc/hosts file.

#::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

3. Make sure below entries are present in /etc/postfix/main.cf file.

#inet_interfaces = all
#inet_interfaces = $myhostname
#inet_interfaces = $myhostname, localhost
inet_interfaces = localhost
# Enable IPv4, and IPv6 if supported
inet_protocols = all

4. Now start the postfix service.

service postfix start