Networking :: CentOS Mail Setup - Sendmail Via External SMTP Server
Jul 30, 2011
I am setting up a CentOS box as a NAT firewall that needs to also send mail. It needs to send this mail using an outside provider's SMTP. The provider requires SMTP over SSL. None of the machines inside the NAT will ever send mail except via the provider's SMTP nor will they ever receive mail except to local clients via the provider's IMAP servers.
So for the example the machine is TESTMACHINE. There is one internet facing ethernet port connected to a DSL modem via pppoe.
The SMTP it needs to send mail via is mail.host.net which requires SMTP over SSL (port 465) and username/password authentication.
The sendmail documentation is quite confusing on how to get this simple setup operating, so an example showing the appropriate changes to sendmail.mc and other require config files.
I've been having this problem since 10.6 released, but have until now been successful with the "just use Thunderbird" response. My sendmail server hasn't been changed, but as clients upgrade from OSX 10.5 to 10.6 suddenly mail.app will no longer connects to send SMTP messages through the server. (IMAP connections to the same server using the same user/pass combinations work perfectly) When I look at the logs, things basically stop right after the STARTTLS command.
Google indicates alot of people are having similar problems, but I'm not seeing any solutions. Do any of you administrate sendmail servers where some of your clients are using Apple's Mail.app on Snow Leopard, and if so what settings are you using? At this point, I'm happy to make changes to the server to accommodate Apple's issue, I have too many Mac users connecting to my server. I just can't figure out what to change. I've enabled virtually every possible login authentication combination, and none of them work.
I have one Centos Server and I want to forward root mail to 1 external account: [URL] I installed sendmail and created /root/.forward with this content: [URL] and I sent a test mail with this command: /usr/sbin/sendmail root <prueba.txt But nothing was forwarded.
After that I ran the same command with the verbose option:
/usr/sbin/sendmail -v root <prueba.txt
And this is the output:
root... Connecting to [127.0.0.1] via relay...
220 localhost.localdomain ESMTP Sendmail 8.13.8/8.13.8; Wed, 3 Nov 2010 21:09:39 -0600 >>> EHLO localhost.localdomain 250-localhost.localdomain Hello myfriend [127.0.0.1], pleased to meet you 250-ENHANCEDSTATUSCODES
For some reason sendmail tried to connect to example.com smtp server and couldn't reach it. I am sure this is because the smtp server for example.com domain is not example.com is mail.example.com. Besides mail.example.com requires authentication, username , password and the smtp port is not the default 25 is 9999. configure sendmail to forward root mail to a smtp server that requires authentication, username, password with a not the default 25 port?
After searching the forum I could not find a clear answer to my question so I am giving it a try...
I have installed a LAMP server with Postfix as mail server. The scripts send email as user www-data using the mail server on the same machine.
However, the email got rejected by external mail servers (failed reverse DNS check) so I setup a mail server that meets all needed requirements.
Now I would like to use this second server instead of the mail server on the LAMP server. I found that this could be done with changing sendmail settings in php.ini (I think).
However I am not sure how that will go: www-data is no actual user on the new email server (which requires authentication before sending). Do I need to create a new user on the email server or change the settings in php.ini to match an existing user?
I have a Fedora 10 machine that I want to setup to send email. However I don't want it to be a full blown SMTP setup.What I am looking to achieve is when something sends email from the local machine (e.g. from cron) to an address I want it to use an MTA on the local machine which will then connect to, and authenticate with, my e-mail providers SMTP server this will then take care of actually sending the e-mail.I don't want, or need, to setup a full blown SMTP service (i.e. only the local machine should be able to use it) so sendmail seems a bit over the top for my needs. Nor do I want to mess about with MX records (am I right in thinking this will mean I have to manage all mail for my domain?).
This is the current setup that we have: We have approx 20 clients who pay us to send out a type of e-mail called an E-Blast to their customers. We currently are using 5 Microsoft Windows Virtual Servers to do this. The problem is that those machines are starting to break down. There are times that it will take Microsoft Windows approx 9-10 hours to complete 1 job. This is way too long. We want to move away from Microsoft Windows for this particular type of job as it seems there are more customers who are wanting to use this type of advertising.
It seems that using a Linux Server "Command Line or Shell" environment would be the best way to go as there is no GUI like Windows. Since there is just text...that is something that would/should process very, very quickly.
I am in the process of setting up a new SMTP outbound mail server. This is the current software & configuration (what is installed on this new machine):
All of the customer data (Names, E-Mail Addresses, etc that these e-mails are going to) are currently loaded in a Microsoft SQL Database.
My machine that I am using is plugged into the DMZ. I have 1 ip address for the 1 network card. I have also added/bound 4 more ip addresses to that network card.
I have configured Postfix for Multiple IP Addresses.
I can, from the command line, send successful test e-mails and receive them in my personal account.
As far as I know everything is setup correctly. I can and will post requested information so that it can be verified that everything is setup correctly.
Here are a couple of my questions:
Ensure that I have my Network / Interfaces file and my Postfix's Master.cf/Main.cf files setup correctly?
How can I setup this server to be an Outbound SMTP server and get it to use all 5 of the IP Addresses to send these e-mails quickly?
What can I use to check and ensure that this server is in fact sending out emails on all 5 IP
Addresses (I heard that there is a program named "Postal" that may help in determing this).
I am running CentOS 5.5 and am trying to get Nagios to send out Emails.
After a bit of reading I have the following in my /etc/mail.rc file:
Code: [root@linux ~]# cat /etc/mail.rc set ask askcc append dot save crt ignore Received Message-Id Resent-Message-Id Status Mail-From Return-Path Via set smtp=172.29.1.76 You have new mail in /var/spool/mail/root [root@linux ~]#
I have Nagios setup correctly and introduced an error to generate an Email but nothing has come through.I suppose I have two questions:
1. Is mail.rc setup correctly? 2. Can I test to see if mail.rc is working correctly?
I am trying to configure sendmail to use GMail to send emails. I followed the instructions at[URL]lay-howto.html but it failed.After I was done with these instructions, I think I "cooked" sendmail... Can no longer configure it and it seems that I will have to start from scratch again...How to get sendmail to send emails using Gmail's SMTP server?
I'd like to have anything that tries to send mail locally on my machine (including crontab reports for instance) to be handled by my ISP's smtp server instead of my machine acting like it's own SMTP server. I've spent around 15 hours trying to figure out how to do this and I keep either getting into things that I don't understand, or hitting brick walls (for instance, I found nullmailer, but after installing it, it seemed like it would only work on Unix) Is there an application like nullmailer which I can use as my MTA to forward all internal mail to a different SMTP?
In Red hat i used the nail command to send mail using an external smtp server without sendmail or other mail services active. My question is: In Centos 5 nail is not present but is present mailx in version 8.1.1-44.2.2
Is there a way to set mailx to use external smtp server ? because in many forum i get the string mailx -S smtp= etc.etc. but in my case the -S parameter generate mailx: invalid option -- S antoher question is there a an official repository to download rpm nail for centos ?
I want to setup sendmail using my username and password on my ISP to be able to send out messages.This is actually true as the mylocaldomain is not a public Internet domain. Just a localdomain for our local network. However, I was expecting that to change to the username in my authinfo "myusername@myispdomain" since this account is authorized to send out email with my ISP.
We have moved from a Windows based SMTP server to Sendmail on Cent 5.5. We have a special application that was written to look at the "BadMail" folder on the Windows box. I am told by my developers that it is capable of monitor remote locations and they just need to know the format or extension of the badmail files.
My question is what is the default location of the badmail folder in Sendmail? This is a default install from CentOS.
i currently installed centos 5.3 with postfix. My old server is centos 4.5 final / new 5.3 final. Old server has sendmail / new has postfix. how can i transfer all the mail and settings from the old to the new? also, the old mail server is mail.xxx.xxx and for testing purposes i named the new mail server mail2.xxx.xxx.
when i an ready to put it into production, the new server will need to be mail.xxx.xxx and the old removed from the system. How do i go about changing the name and making sure everything comes out correct?
I am trying to make my webserver a well respected email sender and it appears to me that using DKIM is something I need to do.
I have no experience with this and would like to know if anyone thinks there are issues that I should be aware of before going down this path.
Also, I have not been able to find any good, STEP BY STEP, documentation on how to set up DKIM with Sendmail.
I am also not sure if you need a certain network configuration for DKIM to work...this is what I am working with:
My webserver (centos 5.3, sendmail 8.13.8) sends outgoing mail and has a valid reverse DNS that matches a forward DNS. The MX records for my webserver's domain point to a third party email provider who handles the incoming mail for that domain. I added an spf record that signifies it that my webserver is authorized to send mail for mydomain.
In order to have greater control over the emails sent out the company I imagined the following scenario.ScenarioDescribing in words what I need.ser sends an email to firstname.lastname@example.org for example, using the smtp of my isp (is the internet).Before the email is sent, the firewall checks if the recipient is blocked transparent, if you are locked out rejects the email.I searched several forums and mailing lists, but did not find scenarios similar to mine.Where found situations in which the mail servers were internally in the company, which is not my case.
This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed:
email@example.com SMTP error from remote mail server after initial connection: host [URL] [ip address]: 550 Access denied...
I am trying to set up a mail server on centos5 using sendmail and dovecot, and eventually spamassassin and some antivirus filter as well. I'd also like to get the proper secure auth mechanism set up at some point too. But for starters, I've been having a lot of difficulty trying to even connect to the mail server from a client computer in the local network. I installed Eudora on the client and after some tweaking in dovecot I was able to connect to the mail server, but then when I try to send an email I get a "connection refused" error, with nothing being logged on the server that I can see.
The last time I set up a mail server was Fedora Core 2, so the configuration files have changed a bit to say the least, and I can't really refer back to those to set up this new server. Does anybody know of a good step-by-step doc on getting the mail server going? I've read the man pages and other various readme's, but these really only list out the available options with no really good explanation of what needs to be done to get the mail server going. If there isn't a full write-up on how to do this, I'll put something together when I'm finished so others can use it in the future.
I have configured Sendmail client to send mail to outside network ( Within local domain ), but i am unable to send any mail as i am getting the following error,
[root@cclx10 mail]# cat test |sendmail -v firstname.lastname@example.org email@example.com... Connecting to [127.0.0.1] via relay... firstname.lastname@example.org... Deferred: Connection refused by [127.0.0.1]
I have the following configuration in my "/etc/sendmail.cf" file
# SMTP daemon options O DaemonPortOptions=Port=smtp,Addr=188.8.131.52, Name=MTA
And netstat is showing that sendmail is listening on Port 25 on the IP address which is mentioned.
This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: email@example.com SMTP error from remote mail server after initial connection: host [URL] [ip address]: 50 Access denied...
I have the 11.4 Gnome Distribution.everything is setup except my email sending.I have never been able to setup evolution correctly with gmail.I have followed the gmail settings of setting the smtp server to be smtp. gmail. com:465 and folowed the instructions here Evolution/FAQ - GNOME Live!to setup smtp.gmail.com with no port change.if there is no port specified the sending message window doesn't report an error it just hangs.
so i set out to change the default smtp port the server uses because my ISP blocks port 25 and i need the email to work in outlook. this morning i could receive email, but not send it. so i did some research and thought that i needed to edit the master.cf file in /etc/postfix/ by commenting out this line: smtp inet n - n - - smtpd -oand replace it with587 inet n - n - - smtpd (587 being the port i want to use)somewhere along the lines postfix server stopped running and now i cannot get it to start.if i try using SSH it crashes immediately and if i restart it in simple control panel nothing happens
I am a bit of a linux newbie, but have been gradually teaching myself how to set up Sendmail 8.13.8 on a CentOS system to handle our MX mail for various domains we own on our local server. Configuration has gone well so far, except I cannot seem to get Outlook to authenticate with the SMTP server and I must readily admit to some large gaps in my knowledge. For testing purposes, I have tried to authenticate using Telnet with the following results:
Code: 220 my.domain.com ESMTP Sendmail 8.13.8/8.13.8; Wed, 3 Aug 2011 14:27:00 GMT ehlo my.domain.com 250-my.domain.com Hello mytelnethost.btcentralplus.com [109.xxx.xxx.xx], pleased to meet you 250-ENHANCEDSTATUSCODES