Sponsored Content
Full Discussion: External SMTP server
Operating Systems Linux Red Hat External SMTP server Post 302937203 by Duffs22 on Wednesday 4th of March 2015 07:31:53 AM
Old 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

SMTP server-denied

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

AIX 6.1 SMTP Server ?

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

Send email from sendmail on AIX using exchange server as SMTP server

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

Can't configure sendmail to send mails to external SMTP Server

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

SMTP Server errors

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

SMTP Server - dump email

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

php code - Sending mail with external SMTP server

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

Any way we can create an SMTP server and use any scripting language to read emails from that server

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

Postfix as smtp server

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

SMTP Server Configuration

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
postal(8)							      Postal								 postal(8)

NAME
postal - program to test SMTP mail server throughput. SYNOPSIS
postal [-m maximum-message-size] [-M minimum-message-size] [-t threads] [-c messages-per-connection] [-r messages-per-minute] [-s ssl-per- centage] [-L] [-l local-address] [-a] [-b [no]netscape] [-[z|Z] debug-file] [-f sender-file] smtp-server user-list-filename DESCRIPTION
This manual page documents briefly the postal program. It is designed to test the performance of SMTP email servers by sending random messages to the specified server as fast as possible. The smtp-server parameter specifies the IP address or name of the mail server that the mail is to be sent to. Mail sent by Postal will not use MX records, this is to allow testing outbound relays etc. If you want to specify a port other than port 25 then enclose the host address in square brackets and have the port address immediately following. If you want a DNS lookup for every connection (for testing round-robin DNS) then immediately precede the host address with a '+' character. To specify multiple servers for round-robin use then sep- arate the addresses with commas. Note that localhost is used for connecting to the same machine. The user-list-filename is the name of a file which contains a list of user's email addresses. This can be just user-names or fully quali- fied email addresses. Whatever you specify will be sent exactly in the SMTP protocol so make sure you do whatever is appropriate. If unsure then use fully qualified addresses (IE user@example.com). The sender-file contains a list of users that will be in the From: field and envelope sender of the messages. If it is not specified then the user-list-filename will be used for the sender list. The maximum-message-size indicates the size in Kilobytes that will be the maximum size of the message body. The size of each message body will be a random number between 0 and the maximum size. Specify "0" if you want just headers to test the connection rate. The default value is 10. The threads parameter is the number of threads that should be created to attempt separate connections. A well configured mail server won't accept an unlimited number of connections so make sure you don't specify a number larger than the number your mail server is configured to handle. Also for sensible results make sure that you don't use enough to make your server thrash as the results won't be representative of real-world use. The default value is 1, this default is not suitable for real tests, it's just for testing your configuration. If you specify multiple server addresses for round-robin use then this number of threads will be created per server, IE 4 servers and -p5 will give 20 threads total. The messages-per-connection parameter is for sending more than one message per SMTP connection. The default value is "1". A value of -1 means to send an indefinite number of messages on one connection (~4 billion). If a value > 1 is specified then the number sent on each connection is a random number between 1 and the number specified. For simulating a mail server connected directly to the net use a value of 2 or 3. For simulating a mail server connected to a front-end relay use a large number. For testing for bugs in your mail server use the value 0 and leave it running for a week. ;) A value of 0 means to disconnect without sending any messages. Good for testing a LocalDirector. The max-messages-per-minute parameter is for limiting the throughput of the program. This is designed to be used when you want to test the performance of other programs when the system is under load. The default is effectively 24000 messages per minute. The local-address parameter specifies which local IP address(es) are used to make the outbound connections. Specified in the same way as the remote address. This is good for testing LocalDirectors or other devices that perform differently depending on which source IP address was used. The -L command specifies that LMTP is to be used instead of SMTP. The -a command turns on all logging. All message data received will be logged. This will make it slow and it may not be able to saturate a fast Ethernet link... The -b switch allows you to specify breakage strings. Currently the only option is for Netscape mail server which strips spaces from the start of subject lines. -b netscape means to avoid leading spaces on subject fields to not break Netscape. -b nonetscape means to always put extra space to test for the bug in Netscape and similar products. Some people say that the RFCs are open to interpretation on this issue, I am interested to see whether anyone else interprets it the way that Netscape does. The -s switch specifies the percentage of connections which are to use TLS AKA SSL. Use 0 for no SSL, or 100 for always SSL, or any number in between. Default is 0. The -z switch allows you to specify a debugging file base. From this base one file is created for each thread (with a ':' and the thread number appended), each file is used to log all IO performed by that thread for debugging purposes. The -Z switch is the same but creates a separate file for each connection as well with an additional ':' appended followed by the connec- tion number. NOTES
When testing mail servers please use domains defined in http://www.rfc-editor.org/rfc/rfc2606.txt - example.com, example.net, and exam- ple.org are all good options. Please don't use anything related to a valid name, since that will cause pain for you and others on the net. RETURN CODES
0 No Error 1 Bad Parameters 2 System Error, lack of memory or some other resource AUTHOR
This program, it's manual page, and the Debian package were written by Russell Coker <russell@coker.com.au>. AVAILABILITY
The source is available from http://doc.coker.com.au/projects/postal/ . See http://etbe.coker.com.au/category/benchmark for further information. SEE ALSO
bhm(8),postal-list(8),rabid(8) russell@coker.com.au 0.70 postal(8)
All times are GMT -4. The time now is 07:38 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy