03-04-2015
External SMTP server
Hi,
We current use an email/hosted exchange server (provided by 3rd party company).
Our production DNS (RH5) server has got the MX rec configured for this 3rd party mail relay server. So in order to resolve hostnames to send outbound mails an A record entry is also required on the external DNS server based on individual servers public IP adddress (in order to relay mails outbound).
The following concern has been raised re security:
- Having public addresses on a public DNS; servers are advertised publically therefore security risk.
In my opinion the production servers are located in the DMZ and so no internet facing IP can traverse onto the LAN without hitting the DMZ.
With the outbound connection configured on the external fw to only allow certain IP address to connect to a certain destination address - so this should remove any risk, as no one would see it.
Question: Would it be better practice to create our own SMTP server and have one public IP address presented to the external DNS server or is this an unnecessary overkill?
...interested in your thoughts/opinions on this.
Regards,
D.
10 More Discussions You Might Find Interesting
1. Solaris
im running Solaris9.
sendmail version 8.13
every now and then my smtp server is being blacklisted resulting to relay denied to some of my client.
what is the very first thing i have to implement?
thanks (1 Reply)
Discussion started by: uwagon
1 Replies
2. AIX
Hello,
Looking for Document how to install / configure SMTP Server on AIX 6.1
is it through smitty menu ? (3 Replies)
Discussion started by: filosophizer
3 Replies
3. Shell Programming and Scripting
i am new in AIX i am trying to write a script to take a backup for specific files on server to and check error log if backup success send email to administrator , script done except for sending mail , i try to configure sendmail on aix to use our exchange server to send emails but still get error... (0 Replies)
Discussion started by: ahmed_salah
0 Replies
4. UNIX for Dummies Questions & Answers
Hi all,I know, that this is very common issue, but I can't find where is the problem... I have Solaris 10 installed.I want to send mail to external SMTP server, like:echo "letter body"| mailx -s "subject" test@test.comBut I donno what kind of changes I have to do in /etc/hosts and sendmail.cf or... (5 Replies)
Discussion started by: nypreH
5 Replies
5. AIX
Hey everyone,
I have an issue where email is working fine in our Windows environments but is blowing up in our AIX environments.
Here is the related functions that are getting called:
int get_smtp_line( void )
{
char ch = '.';
char in_data ;
char * index;
int retval = 0;
... (4 Replies)
Discussion started by: ctote
4 Replies
6. UNIX and Linux Applications
Background:
I am replicating a set of servers into a "bubble" for testing. Those systems cannot be aware they are in a "bubble" so I must replicate all external services. I have successfully replicated most of those services except SMTP. I would like to configure an SMTP server that collects... (0 Replies)
Discussion started by: NFN_NLN
0 Replies
7. Shell Programming and Scripting
Here is the code:
<?php
//new function
function loadini($path) {
$fp = fopen($path, "r");
$fpcontents = fread($fp, filesize($path));
fclose($fp);
return $fpcontents;
}
$to = "test@test.com";
$nameto = "notme";
$from = "test";
$namefrom = "Who From"; ... (0 Replies)
Discussion started by: galford
0 Replies
8. Ubuntu
Is there any way to create an SMTP mail server will all granular permissions to it so that I can read emails which that server receives through any scripting language and also reply from the same server automatically? (3 Replies)
Discussion started by: sandeepcm
3 Replies
9. UNIX for Dummies Questions & Answers
hi guys
I have to configure a SMTP server using Postfix, ok let me tell the domain is located at godaddy so my smtp postfix server has to use that domain let's say mycompany.com
so anyone knows how to configure postfix using this way?
or postfix is easy to configure?
thanks a lot (3 Replies)
Discussion started by: karlochacon
3 Replies
10. Web Development
Hello list,
I want to be able to send email directly from my linux box. I have both a CentOS and Debian installation. I am by no means an expert when it comes to all of the SMTP servers. I have been testing different configs by installing and uninstalling sendmail, postfix, and exim4.
... (2 Replies)
Discussion started by: landossa
2 Replies
LEARN ABOUT SUSE
tnm::dns
dns(n) Tnm Tcl Extension dns(n)
__________________________________________________________________________________________________________________________________________________
NAME
dns - Query the Domain Name System of the Internet.
_________________________________________________________________
DESCRIPTION
The dns command allows to query the Internet Domain Name System (DNS) (RFC 1034, RFC 1035, RFC 974, RFC 1912) for host information. The
main purpose of this command is to convert host names into IP addresses and vice versa. The dns command also allows to retrieve host infor-
mation records as well as mail exchanger records.
DNS COMMAND
dns [options]
Invoking the dns command with options but without any command arguments allows to retrieve and change the default values. See the
description of supported options below. Default values are bound to a Tcl interpreter which allows to have multiple Tcl interpreter
with different defaults.
dns [options] address host
The dns address command sends a query to retrieve the address record for the specified host. The command returns the list of IP
addresses for the given host name.
dns [options] name address
The dns name command sends a query to retrieve the domain name pointer record. A pointer record maps an IP address to a fully quali-
fied domain name (FQDN). The command returns the fully qualified domain name for the given IP address.
dns [options] hinfo name
The dns hinfo command sends a query to retrieve the host information record. The command returns a list containing two elements. The
first element describes the hardware type and the second element the operating system.
dns [options] mx name
The dns mx command sends a query to retrieve the mail exchanger record. The command returns a list of mail exchanger records if name
is a domain name for which one or more MX records exist. Each element of this list contains a full qualified domain name (FQDN) and
its priority.
dns [options] soa name
The dns soa command sends a query to retrieve the start of authority record for a DNS domain. The command returns the name of the
authoritative DNS server of the DNS domain name.
DNS OPTIONS
-server server
The -server option defines the DNS server which will be used to process the request. The default value is the default DNS server
configured on the local system.
-timeout time
The -timeout option defines the time the dns command will wait for a response. The time is defined in seconds with a default of 2
seconds.
-retries number
The -retries option defines how many times a request is retransmitted during the timeout interval. The default number of retries is
2. Please note, that many resolver double the last timeout after every retry.
SEE ALSO
scotty(1), Tnm(n), Tcl(n)
AUTHORS
Erik Schoenfelder <schoenfr@gaertner.de>
Juergen Schoenwaelder <schoenw@cs.utwente.nl>
Tnm dns(n)