This solution will cover cPanel Issues, Email Issues and tagged cPanel disable IPv6 in Exim, Disable IPv6 in Exim on cPanel server, IPV6 issue with exim on cPanel server.
Many times, it happens that sending emails to Gmail or few other ISP’s are getting rejected when Ipv6 networking is enabled on the server.
This is basically because, exim attempts to deliver the emails using IPv6 network by default and some times it returns the message “Network is unreachable“, specially to Gmail addresses.
This can be easily fixed by forcing exim to deliver the emails using the IPv4 IP address instead of IPv6 address.
You can follow the below simple steps to disable IPv6 in exim configuration ::
Login to ” WHM < GoTo > Home » Service Configuration » Exim Configuration Manager » Advanced Editor ”
Scroll down until you see “ Add additional configuration setting ” (it’s just above Select: “ BEGINACL “).
Then, select the following option from the drop-down menu above:
* Select > disable_ipv6
and set the value to ” true ”
As : disable_ipv6 = true
for u for Admin 