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Email and FTP down

Posted on 2006-06-13
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Last Modified: 2013-11-29
Hello,
     Last Friday in the afternoon the ablility to receive email out externally errored out.  I didn't change anything I was just unable to receive messages after a certain time frame.  I was still able to send internally though.  Through many trial and errors, I am now unable to send or receive email from anywhere.  I first removed the port forwards for POP3 and SMTP and reentered them, this has caused me not to be able to connect to ports 25 or 110.  I use the command telnet mail.domainname.com 25 and I get the Could not open a connection to the host.  Our satelllite site is also unable to FTP anything too us.  Any help is much appreciated.
Thanks
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Question by:theret79
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26 Comments
 
LVL 32

Expert Comment

by:jhance
ID: 16894386
Obviously there is a problem but based on what little you're said, it would be difficult to do anything but guess...
0
 
LVL 13

Expert Comment

by:prashsax
ID: 16894758
TRy this from outside your network.(Maybe from your house, or dialup internet connection)

telnet mail.domainname.com 25

telnet ftp.server.com 21

telnet mail.domainname.com 110

If you can access these, your router is fine.

If not, the your port forwarding is not working.

Just to be very sure, try all the above command from within the network as well.

If you can do it from within the network and not from outside, then problem is caused by router/Firewall.

If you can't even access from within the network then check the services on the Server.
0
 

Author Comment

by:theret79
ID: 16895070
I tried doing all of those from internally and externally and no go.  I am able to RDP in and PcAnywhere in, but no email and no FTP's are getting through.  What services on the Server could be stopping this?  
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LVL 13

Expert Comment

by:prashsax
ID: 16895113
Ok, If its exchange then you need to check SMTP service is running or not.

Check if POP3 service is running or not.

To check the services,

Run->services.msc

Locate SMTP Server service and Exchange POP3 Service.
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Author Comment

by:theret79
ID: 16895139
unfortunately it is Linux Sendmail.  And the POP3 service is running, Do you know how to check the SMTP service on Sendmail?
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LVL 13

Expert Comment

by:prashsax
ID: 16895190
See, if your Sendmail MTA is running.

Its listed with name procmail in the running process list.


use "top" for the process list.

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Author Comment

by:theret79
ID: 16895233
procmail is not listed in the process list.  What is the process for POP3?  I might be mistaken as to whether it is running also.
0
 

Author Comment

by:theret79
ID: 16895346
sendmail is running for sure I saw it in the listing.  
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LVL 13

Expert Comment

by:prashsax
ID: 16895376
Do you see something in the logs.
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Author Comment

by:theret79
ID: 16895390
No I don't see anything in the logs
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LVL 13

Expert Comment

by:prashsax
ID: 16895392
What do you get when you type:

sendmail -bd

Does it show some errors.
0
 

Author Comment

by:theret79
ID: 16895418
no errors
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LVL 13

Expert Comment

by:prashsax
ID: 16895426
OK, now if you do

telnet 127.0.0.1 25

does it show you something.
0
 

Author Comment

by:theret79
ID: 16895439
It connected on the mail server, but on the PC and Domain controller no connection.
0
 
LVL 13

Expert Comment

by:prashsax
ID: 16895460
Then someone must have enabled firewall on your linux box.

See, if you are using IPchains.

What rules are configured.
0
 

Author Comment

by:theret79
ID: 16895479
how do I see if IPchains is running?  Do I use top again?  Sorry about this I am new to using Linux.
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LVL 13

Expert Comment

by:prashsax
ID: 16895519
Ok, just write

iptables

this will print all the rules.


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Author Comment

by:theret79
ID: 16895550
it says iptbables v1.2.3: no command specified.
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LVL 13

Expert Comment

by:prashsax
ID: 16895579
Yes,

You need to type

iptables -L

This will list all the rules.
0
 

Author Comment

by:theret79
ID: 16895636
/lib/modules/2.4.7-10/kernel/net/ipv4/netfilter/ip_tables.o: init_module: Device or resource busy
Hint: insmod errors can be caused by incorrect module parameters, including invalid IO or IRQ parameters

/lib/modules/2.4.7-10/kernel/net/ipv4/netfilter/ip_tables.o: insmod /lib/modules/2.4.7-10/kernel/net/ipv4/netfilter/ip_tables.o failed

/lib/modules/2.4.7-10/kernel/net/ipv4/netfilter/ip_tables.o: insmod ip_tables failed

iptables v1.2.3: can't initialize iptables table 'filter' : iptables who?

Perhaps iptables or your kernel needs to be upgraded

0
 
LVL 13

Expert Comment

by:prashsax
ID: 16895648
use ps -x command to list the all running processes.

To diable iptables completly use this command.

chkconfig --level 1235 iptables off

This will disable iptables from being started at startup.

Don't use this if your linux machine is sitting on internet without any network firewall.
0
 
LVL 13

Expert Comment

by:prashsax
ID: 16895678
So, iptables is not running.

perhaps some other firewall is running on your linux server.

Because if you can access port 25 from local machine and not from any other machine on the server. This points to a local firewall running on the machine.

Use ps -x to list all the running processes.

The firewall could be IPchains/NetFilter etc.
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Author Comment

by:theret79
ID: 16895694
I don't show IPchains running, It says sendmail is accepting connections though
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LVL 13

Accepted Solution

by:
prashsax earned 1600 total points
ID: 16895715
Is it accepting connection on port 25 from other servers in your network now.






0
 

Author Comment

by:theret79
ID: 16895745
It works you are a life saver I don't know what was holding it up but you did it.
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LVL 13

Expert Comment

by:prashsax
ID: 16895804
I think it was IPTables.

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