Mail server down

[emmons]

Help!

My mail server was working perfectly for months until this weekend. I was out of town when a new (external) firewall was put in and now the mail server is down.

Can anyone tell me where to start?

Thanks

 

[sleipnir214]

Define "down" as you are using it here.

Want the best answers? Ask the best questions:

http://www.catb.org/~esr/faqs/smart-questions.html

TANSTAAFL!

 

[emmons]

Yes, I agree. I must ask the right questions. Problem definition is always the hardest part of solving anything.

OK. In the past, when I type in the URL for my mail server the squirrelmail login page comes up.

*Now* I get this:

The page cannot be displayed
The page you are looking for is currently unavailable. The Web site might be experiencing technical difficulties, or you may need to adjust your browser settings.

What would be your suggestion to try?

 

[sleipnir214]

Would I be correct to assume that this is from a machine that is on the other side of the firewall from the mail server?

If so, it sounds to me like somebody needs to punch holes in the firewall to allow access through to the server on the appropriate ports.

Want the best answers? Ask the best questions:

http://www.catb.org/~esr/faqs/smart-questions.html

TANSTAAFL!

 

[emmons]

OK. I visited the library where the mail server is. I have more info.

Mail can be sent and received inside the local area network-intranet.

From outside the building (the other side of the firewall)- we do think mail gets past the firewall because the message says allow smtp port 25 BUT *then* it says deny smtp-proxy. We are not getting mail from outside or able to send it to the outside. The mail server is now in a "DMZ" if that sheds any light.

Thanks for your help.

 

[emmons]

p.s.

I am still getting this message from home

The page cannot be displayed
The page you are looking for is currently unavailable. The Web site might be experiencing technical difficulties, or you may need to adjust your browser settings.

So I can't even try to login to squirrelmail from home. I can from the library where the server is but mail won't go outside the lan.

-help?

 

[tarn]

Mail "could" require any of the following ports:

25 SMTP
110 POP3
142 IMAP

And if you are using squrrielmail (safely) then you should probably be doing so over SSL (

https://)

so that adds another port (443) into the pot.

You could test all of the former from a telnet prompt on your external client:

telnet server.url.com 25
telnet server.url.com 110
telnet server.url.com 142

usually these will return some form of banner, anything else then there is probably a firewall rule for those ports that says "no access"

Good Luck.

 

[bluegroper]

Problem looks like its the firewall, not the mail server.

 

[emmons]

does anyone know how I change the subnet mask on my linux box?

 

[tarn]

Look at /etc/sysconfig/network-scripts/ifcfg-eth{n} where is {n} is the interface file you need to configure "if you have more than one"

vi that file then bring the interface down and up again (this will sometimes go with "system network restart" but not allways).

Good Luck.
Laurie.

 

[emmons]

Thanks. I changed the default gateway to the correct one but I still cannot connect to the mail server from outside the library.

Dang it.

 

[sleipnir214]

Insufficient data for a meaningful answer.

On what network are the machines inside your firewall? Routeable? Non-routeable? This can make a difference for NATting rules.

What kind of firewall are we talking about here?

What are the rules allowing outgoing traffic?
What are the rules allowing incoming traffic?

Want the best answers? Ask the best questions:

http://www.catb.org/~esr/faqs/smart-questions.html

TANSTAAFL!

 

[emmons]

Yippee!

Problem is solved. When I said "I changed the default gateway to the correct one but I still cannot connect to the mail server from outside the library" that, as it turns out, was a big lie.

However, now I did change it to the correct number and it works just fine.

Thanks for listening and especially for telling me how hosed up my questions are. I always enjoy that part.