Linux mail server mail's sending issue.

Linux sending mails issue.

Error Log in the mail log:

                             SYSERR(root): collect: I/O error on connection

      premature EOM :collect: I/O error on connection

1 Most of the time checks the ISP connection

2 Check sever and the router network card MTU values are same if not you have to mach both the value.

eth1      Link encap:Ethernet  HWaddr 00:0C:29:90:DC:6A

          inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0

          inet6 addr: fe80::20c:29ff:fe90:dc6a/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1492  Metric:1

          RX packets:452077 errors:0 dropped:0 overruns:0 frame:0

          TX packets:527959 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:183771342 (175.2 MiB)  TX bytes:561176564 (535.1 MiB)

Default value is 1500.

Some router is only support less that 1500 so

Second option is change server MTU value.

·         How to change the MTU value in the mail serve r?

vi /etc/sysconfig/network-scripts/ifcfg-eth1

DEVICE=eth1

ONBOOT=yes

IPADDR=192.168.1.1

NETMASK=255.255.255.0

GATEWAY=192.168.1.254

TYPE=Ethernet

MTU=1492

Restart the network service. 

# /etc/init.d/network restart