I want to write some email scanning software and don't understand how to setup my server. I have a hosted web server running Windows 2003 Server. It is running the Default SMTP Virtual Server with a fully-qualified domain name of abcdef.com (example). DNS is pointing abcdef.com to my server. If I spoof an email from my desktop pc so that it appears to come from info#abcdef.com, and I send the email to a 'non-existant' email address then the bounceback does arrive on my web server and is stored in C:\inetpub\mailroot\Queue on the server - great! (I can scan it and handle the bounceback). However, if I simply send an email straight to info#abcdef.com then it does not seem to get placed anywhere on the server. I don't understand why bouncebacks get stored but other incoming email doesn't. I'm keen to avoid having to install any 'email server software' on the server, as I want to keep things as clean as possible. All I really want is some way of telling the server to accept all incoming messages to abcdef.com so that I can process them myself, and to place the .eml files in a known directory that I can scan. I'll then write an eml file parser to process the files.
Thanks very much.
A possible reason for the lack of delivery is that your domain has a DNS A record, but no DNS MX record. MX records are used for delivery of mail. Historically, if no MX record was present for a domain, mail servers were supposed to fall back to looking for a domain's A record.
In your case, I'd guess that your local mail-sending software is looking for an MX record and then stopping if it doesn't find one, whereas the remote system sending you the bounce is looking for the MX record and then looking for an A record when it can't find one.
The Wikipedia article on MX records has more details.
SMTP is a message transfer agent (MTA), responsible only for handling the transfer of mail from one point (the client, perhaps) to another (the mailbox server, such as a POP or IMAP server). SMTP servers aren't the right tool for ultimately handling mail coming INTO a domain -- they only handle transferring the mail coming into a domain to another app, such as the aforementioned POP or IMAP server, which then know how to sort and store that mail.
In short, the Default SMTP Virtual Server isn't the tool you're looking for for your project.
From this other StackOverflow question, it looks like there are a few SMTP servers which are intended for development use but which might serve the purpose you seek -- they accept incoming messages and then write them to files (in some manner, and with some tweaking).
Ok, working now. Issues were as follows:
There was no MX record, so external email wasn't being directed to the server. The .EML file that existed on the server was indeed placed there by an outbound email process.
The firewall was blocking port 25 - now opened.
It is necessary to have some sort of inbound email service running on the server. Windows Server has a lightweight POP3 service which you can configure to place all incoming email into a single 'catch-all' mailbox. This fills with .EML files, which can then be scanned by our custom service.
Many thanks to delfuego & Jon.
Related
I have a Coldfusion page (CF10) that creates a report and sends it via cfmail to a list of recipients. The ones in our internal domain are receiving, but the external addresses are not.
I found a couple threads where people were having the exact same problem, and the solution was to add the CF server's IP address to the Exchange server. So our IT guys did just that - they added the IP addresses of all of our production servers to the receive connector on the Exchange server. However, the mails are still not being relayed, and I'm continuing to get the same message in the mail log:
javax.mail.SendFailedException: Invalid Addresses; nested exception is: com.sun.mail.smtp.SMTPAddressFailedException: 550 5.7.1 Unable to relay
I'm not familiar with everything that needs to happen to make the Exchange Server relay email to external addresses. Adding the IP addresses to the receive connector obviously isn't enough. Are there other steps that need to be performed?
Coordinate with your IT guys. Write a ColdFusion page that they can run that sends mail to an external address they can access. Then tell them to do what they have to do to receive mail at that address.
Solution was simple - we originally specified the mail server in the cfadmin mail settings, but included no username/password. That worked fine, until we wanted to start sending cfmails to addresses outside of our own domain. So IT created a dedicated "Noreply" account for this purpose, and I entered the username/password in the cfadmin mail settings.
I have an account with an internet provider, the majority of my company is based on the mail server they provide which is a bog standard UX style server from what I can tell. They offer the ability to edit the DNS records in the admin login, and you can edit the MX records.
What I want to do is introduce a subset of email accounts that are managed by a second mail server, this being an MS Exchange server. So what I want, I think, is to configure the Authoritative server as the 1and1 server, and configure the Exchange server as a non-Authoritative server and have the Authoritative server forward all non local addresses, or specified addresses, on to the Exchange server. Thus all addresses would look the same old_mx#ab.com and exchange#ab.com, but they would be resolved by different mail servers, working in tandem. My assumption had been you could specify a destination for unresolved e-mail addresses before they are declared void and bounced.
I spoke to a support engineer at 1and1 who said it was possible but they needed the exchange server address. Seemed reasonable, MS seem to think it's possible and provided an address. I just phoned the ISP back with the Exchange server details as provided by MS... and the next engineer says it isn't possible.
Can we confirm this is possible firstly, and how would I go about configuring it?
Not much help has been forthcoming on this question, but I do have some leads on answers myself. It would seem that there is no DNS record solution to the problem, not one commonly supported anyway. The DNS can only really be used for primary and secondary MX definition.
The only way to set this form of triaged MX server seems to rely on the MS Exchange server being defined as the first link in a chain of mail servers. i.e. The DNS referenced server. Once this is done the MS Exchange server can be configured as a non-Authoritative reference, within the server. Once that is done the MS Exchange is then provided with the subsequent servers to reference. On receipt of an e-mail that the MSE server doesn't recognise it will then forward the mail to another server that might be another non-authoritative MSE or an authoritative server of any description. The end server would then be responsible for returning any error messages back to the sender.
If anyone finds a better solution that doesn't involve redefining the master mail MX records I would be very interested, as I don't really want the MSE setup as the primary MX record.
I recently switched from an axoim exchange mail server to microsoft 365 exchange server. Now my email address is still the exact same as it was, and most of the incoming mail comes to my new server and address, but it looks like some incoming mail is still going to the old server. Why is that and what can i do to address it?
I'm assuming that you changed the MX records for your domain, so that they now point to Microsoft 365's mail servers, correct? If so, it may take a day or two for the DNS changes to propagate.
Following Problem: I have written a mailing-list via PHP, SwiftMailer and Postfix. On my Old server it worked without any problems, but Since I moved to another Server (Exactly same configuration, but other IP) the list-mails stuck in the Spamfilter of the Receivers. (Espacially in Google Mail)
Is there anything I have to do escept rerouting the URL DNS-Records, that Google sees, that "I am that Server" and the mail is no spam?
First, check that your outgoing mail server is identifying itself correctly in the HELO command (or EHLO command) when it connects to a receiving mail server. There should also be an A record for this name that should point to the IP address of the mail server. Also, this IP address should reverse to some name (possibly, but not necessarily, the same name as above), and this name should point to the mail server's IP. If any of this is not right, then most spam filters will not consider your server to be a 'real' mail server, and will most likely flag any message sent from your server as spam. This is how many spam filters block spam that originates from computers that have been taken over as 'zombies'.
Another thing to do is to check that you mail server IP is not on any blacklists. You can use MXToolbox for this: http://mxtoolbox.com/blacklists.aspx
Another thing you can do is use port25's verifier tool. This tool will spot any red flags that might be causing your messages to be flagged as spam. See http://www.port25.com/support/authentication-center/email-verification/ for more info.
Last but not least, you might want to setup an SPF record for the domain that you are sending these messages from, to indicate that the IP of your mail server is authorized to send mail from this domain. This will help a lot. For more info, see: www.openspf.org.
This is a problem I'm sure is easy to fix, but I've been banging my head on it all day.
I'm developing a new web site for a client. The web site resides at (this is an example) website.com. I have a PHP form script to email visitors' requests to requests#website.com.
When I coded this on a staging server on a different domain, all worked fine. When I moved it to website.com, the mail messages never arrived. The web server is on a virtual host with a major ISP.
Here's what I've learned since then: My client's mail server is Microsoft Exchange on a box physically in their office. Whenever someone on the outside world emails requests#website.com, the mail arrives. But if the web server sends to the same email address, it fails every time. This is not a PHP problem. I secure shell in to the web server and have tested this both with sendmail and the UNIX mail application. I've also tested it by emailing various email accounts from the shell. I can email myself, for example, just nobody at the website.com domain.
In short, when I'm logged in to website.com, mail to requests#website.com, user#website.com, another_user#website.com all fail. All other addresses work fine. What I've discovered is those dropped emails are routed to the web server's "catchall" account where they sit in its inbox.
I've done an MX lookup on website.com. The MX record points to mailsec.website.com. I can telnet to mailsec.website.com port 25 and see the SMTP server.
It appears to me that website.com isn't doing an MX lookup when it's sending mail to requests#website.com. My theory is that it recognizes the domain as local, sees that there's no "requests" user account to deliver it to, and drops the mail into the catchall account. What I want is to force sendmail to do the MX lookup and send the message on to the Exchange server. I'm at wit's end here. I can't figure out how to do this.
For that matter, I may be way off base here and have misdiagnosed this entirely. Internet mail and MX has always seemed a black art to me, and my ignorance is certainly showing in this question.
I think the problem is that sendmail (your process) is talking to the local sendmail daemon. The local sendmail daemon thinks that because it is website.com, it should know how to deliver the email. Unfortunately, the actual address in the to field does not exist on the web server and thus it dumps it in the "catchall" mail box. You should talk to your ISP and have them update their sendmail configuration so that mail addressed to ...#website.com gets forward to the mail exchanger instead of being handled locally.
Sendmail by default guesses list of local email domains.
It can be turned off using the following line in your sendmail.mc file:
define(`confDONT_PROBE_INTERFACES',`True')
As root list local email domains before and after the change using:
echo '$=w' | sendmail -Am -bt
You will see which domains should be added "manually" to (usually) /etc/mail/local-host-names file after disabling auto-guessing.
After changing sendmail.mc:
Generate/compile new sendmail.cf file
Restart sendmail daemon (or send HUP signal)
tvanfosson basically has it, but as a temporary workaround, you should be able to change your script so that it mails 'user#mailsec.website.com', and then the mail will get delivered to the actual mail server.
Edit the tsm.cf file (in /etc/mail/ or similar) to include
FEATURE(relay_entire_domain)
between the DOMAIN() and MAILER() lines. Since you're editing the file, you may want to also improve security with
define(`confPRIVACY_FLAGS',``noexpn,novrfy'')
After changing the tsm.cf file (or any sendmail config file), restart or SIGHUP the sendmail process.
This change is necessary because the WWW and MX servers for the domain do not exist in the same process space; this FEATURE triggers sendmail to process messages for the domain using it's external delivery mechanism.
The edited portion of the tsm.cf file should look similar to this:
DOMAIN(website.com)dnl
FEATURE(relay_entire_domain)dnl
define(`confPRIVACY_FLAGS',``noexpn,novrfy'')dnl
MAILER(smtp)dnl
MAILER(procmail)dnl
What worked for me was to add an MX record on the webserver hosting the website, that points to the host assigned on the original domain name server. In the case presented here would be an mx record pointing to: mailsec.website.com
I'm new here. Wanted to extend RB_CWI answer, but I am not allowed to comment.
His solution worked great.
You are not required to define the DOMAIN().
However, on my system I was required to install the sendmail-cf package.
The instructions below were done on CentOS 6.5
First, install sendmail-cf
sudo yum install sendmail-cf
Then, edit the senmail.mc
sudo vi /etc/mail/sendmail.mc
At the bottom of the file add FEATURE(relay_entire_domain)dnl, so it looks like:
...
FEATURE(relay_entire_domain)dnl
MAILER(smtp)dnl # right above this line
MAILER(procmail)dnl
dnl MAILER(cyrusv2)dnl
Save the file, and restart sendmail.
sudo service sendmail restart
Got stuck on the same problem. MX points to an external Exchange server but php/sendmail did not lookup this record. Instead mails posted by WordPress on this webserver dropped in the catchall-mailbox.
Solution was to delete ALL mailboxes on the webserver. Now sendmail was interested in the MX and all mails went to the Exchange.
However, the Exchange uses the webspace's mail server as SmartHost for outgoing mails. As solution for this, we were able to use the FTP credentials for accessing the mail server. I assume this solution does not work on every provider on this planet, but in our case (all-inkl.com) it worked out.