procmail and delivering to an IMAP server? - email

I run my own mail server. It uses procmail to filter incoming mail, which is then stored in maildirs and gets served out my MUA using IMAP. I've got about 1.5GB of email is 135000 inodes.
This all works very nicely. However, I'd rather like to stop using maildir and switch to something more efficient --- maildb, or Dovecot's dbox, for example. Unfortunately, procmail can only deliver to a very limited set of backing store formats (Maildir, MH and mbox, AFAICT).
What I'd really like to do is to persuade procmail to deliver email via IMAP, rather than writing it directly to the backing store; this means that I can change the backing store format whenever I like without needing to reconfigure procmail. But I can't find any way of doing this. Any ideas?
(I'm also interested in any other mail filter tools that work like procmail but support IMAP. The only other filter tool I know is maildrop --- but that has similar restrictions to procmail.)

Okay, here's a proper solution.
The cone project (http://www.courier-mta.org/cone/cone00index.html, Debian project: cone) has a very handy tool called mailtool which will copy files between mailbox types, including remote IMAP servers.
So, to deliver a message to a remote mailbox, you need a script which:
writes out the incoming message to a file (which becomes a one-message mbox folder)
does mailtool -tofolder destinationfolder -copyto imaps://username:password#server.com mbox:/full/path/to/message.mbox
That will then upload the message.
I don't actually need to do this any more so don't have a prepared script to post, but of the eight or nine different IMAP tools available, this was the only one that would actually do this, so it's worth documenting as such.

As a partial answer to my own question, it seems that Dovecot does come with a deliver tool specifically designed for this kind of thing; it works from procmail with a line like:
| /usr/lib/dovecot/deliver -m "Folder.Name"
...and it figures out all the rest of the settings automatically.
So now I can change the Dovecot mail storage format and everything will still work; but I'd still like an approach that actually uses IMAP to deliver the messages, so that I can try IMAP servers other than Dovecot's.

Related

Possible to use server for collecting and distributing mail

We currently have POP3 mail accounts where I am and try as I might to convince my manager that we should be using hosted IMAP or Exchange he won't budge because of the cost. The staff are mostly out of office so there is no domain server here, however, we do have a dedicated server and I wondered whether I could use this to collect the mail and distribute it from there in some way.
Effectively what I'm trying to do is ensure mail is stored somewhere other than the end users machine because backups are user dependant at the moment. With hosted Exchange or Exchange on this server would be simple but my manager won't shell out for it. I have seen free mail servers called MailEnable and Axigen but unsure if they will do the job. Sorry if this seems like an easy or stupid question but never needed to do this before.
I am assuming due to the reference to Exchange that you are on Windows.
If you have an old box lying around that works, you could install linux on it and then choose from a number of different imap servers. Dovecot and Courier are both good choices and I have worked with them before.
You could use fetchmail to then pick up the mailboxes and then deliver to the imap boxes or get them deliver directly.
Setting up such a linux server for email was one of the first things I ever did on Linux. While initially daunting, once you get the hang of it, it is pretty straightforward and there are plenty of resources out there to help.
Ubuntu is probably the easiest to get used to. CentOs is also a reasonable choice.
You shouldn't be running your own server if you aren't willing to administer your own server, and they are not easy to configure if you don't know what you are doing (e.g., you mess up and you are exploited for spamming).
Look into a service like mailgun. In my application we are using them for forwarding to REST endpoints as well as onto another SMTP server.
Competitors that wound up not meeting my needs but may meet yours include Dyn, email yak, Sendgrid, etc. etc.
Why not just setup the mail clients to store their mail files on a standard network drive or share? I follow that this situation is pretty silly in your view - 100% because of the ridiculous constraints that you are being asked to work within: I would similarly find the solution I am suggesting ridiculous generally; but under the circumstances, it seems like a simple answer to your problem - replacing distributed mail storage and backup with centralized storage and backup.
Don't POP3 email clients have the option keep a copy on the server? Mine certainly does. See second tick box on the pic.
You can then periodically take a back up of all the emails from the server to stop it getting clogged up.

Transfer emails to new hosting?

A client is moving from their old hosting to mine. They have a few email accounts on the old hosting and I want to move all the emails on the old hosting to mine. How can I do this? If I download them with POP can I then upload them to the new hosting?
The answer depends on the mail server that you are using. Yes, you can download all the mail messages with POP3, but the upload to your mail server will depend on the type of mail server. I am not aware of any mail servers that provide a tool to import mail messages.
Most mail servers store the email message in a file, and you can certainly drop the files in the folder where they are stored, but that does not mean that it will be visible, you will have to deal with how the mail server index those files.
I suggest looking at the specifications for your mail server.
If you access both accounts with IMAP (most hosts support this now) instead of POP, you can literally drag and drop the messages between folders/inboxes for the two email accounts.
Also, depending on the type of hosting they're moving from/to, you may be able to use a feature of your new server's control panel to do the importing...unless you're doing it manually on a vanilla VPS or dedicated. There are still options, but you'd need to confirm here how your new server is setup and what the old server looks like.
If you're only talking about a couple of accounts with a few folders each, you may just want to consider IMAP as your path of least resistance. The transfer will primarily depend on your own Internet connection, as most hosting companies have connections faster than yours.
Lastly, if both servers share a similar format for the mailbox, you might want to just rsync the email over to the new server (assuming you have root access on both servers) to the proper email directory. Depending on the email box format, you may be able to simply run a server command to "convert" the mailbox to the format your server is expecting.

What's the most straightforward way to delete emails marked as spam by SpamAssassin?

I'm on Ubuntu Intrepid, using Postfix and SpamAssassin. I've seen approaches using procmail (like the one suggested # Apache), but I'm looking for a solution that does not use procmail.
This is a programming question because the correct answer will be some form of code that accomplishes the task at hand (my response to the negative votes).
UPDATE to the situation: I used this tutorial and it worked out excellently: https://help.ubuntu.com/community/PostfixAmavisNew
It really depends at which level you want to delete the spam:
At the mail client level, using Email client rules (like the ones available in Thunderbird) is easy: just set a rule that delete any email marked as SPAM in the subject.
At the user level, if mail is received automatically by the machine, you could set some cron job that periodically inspect the local mailbox and again delete mails marked as SPAM.
It's easy if your local store uses maildir since each email is just a file, as opposed to the mbox format which would require some more work since it's a single file.
Setting up maildir for postfix is trivial.
At the server level, using Amavisd will allow you to have more control over how mail is handled.
Amavisd has threshold settings where you can define an evasive action depending on the spam score given by spamassassin.
For instance, anything above 15 points is put in quarantine and anything above 30 points is deleted.
There are some instructions for installing Amavisd on Ubuntu.
The point is, as far as I know, spamassassin's job is to identify and give spam points to emails. How you want these to be handled is not up to spamassassin but the other modules down the chain.

programmatically sending out emails from a linux server

I want to send out one off emails from a linux server. The server does not need to receive emails back.
Is there a simpler solution than sendmail for sending outgoing emails only?
I would prefer to use Perl to send the email.
Calling out to /usr/lib/sendmail is usually the preferred method because it handles delivery problems correctly. This does not mean using sendmail. Most (all?) mail transport system provide a command that's just named sendmail and provides an interface compatible to the original.
Alternatively you can send directly through a SMTP relay using a package like Net::SMTP but be extra sure to correctly cater for delivery problems.
Sendmail is not the only choice. you can use Postfix, Qmail, and many others
my Perl scripts call the mailx command. to know how to use it, type 'man mailx'
However this require to have a MTA correclty configured.
Or you can just use the Net::SMTP perl library and use your smtp server of choice
I have used msmtp successfully, ie it supports great authentication
TJ Luoma did a nice writeup of it on TUAW
I find nullmailer a very useful solution for the described scenario. Nullmailer is a sendmail/qmail/etc replacement MTA which relays to a fixed set of mail servers. It is very simple to configure and consumes little resources.
One important advantage of nullmailer over other mentioned solutions like mstmp and ssmtp is that it maintains a queue of emails to be sent. The application sending the mail is blocked only a very short time while the mail is queued (milliseconds). The sending of the mail happens in the context of a another process.
Solutions like mstmp and ssmtp don't maintain a queue of email. The sending happens in the context of the application, thereby blocking the application. Sending an email this way can easily take 1 to 2 seconds or longer. This may not be a problem in many cases but can become a problem if the email is sent by a web application.
http://untroubled.org/nullmailer/
You do not need a mail transport agent (MTA) instance on the machine doing the sending if you have another mailserver already running in your organization: you can make Perl deliver the email through SMTP to that server, so there's no need for having (another) MTA like sendmail on "your" machine.
I'm fond of creating a gmail or other free account and then using the java mail api in J2EE to send messages (from your new gmail account) to whoever... Typically i'll create a Mailer class which can be constructed with a default constructor and then give it a send(String dest, String subj, String body[, Obj attach...if you want]) and then in your case you might wrap the thing in a main method so that you can call it from else with some command line args, or call from within some java program. If you interested i'll shoot you the code.
I know you said perl, but the simplest cross-platform email sending library I have used is python's smtplib. Certainly worth a look.

Method for email testing

I am writing a program that will be emailing reports out many (~100) clients which I want to test before I spam everyone.
I want to do a test run against my production data and actually send the messages to a SMTP server, but I don't want the SMTP server to actually deliver the messages. I want the server to act like a real SMTP server from the perspective of my application, but instead of delivering messages, I just want it to store the messages, and log what happened.
Is there a SMTP server specifically designed for testing purposes?
Does anyone know of a way to configure exim or postfix to behave like I have described above
What do you use to test a mass-email delivery?
In java you can use dumbster
Its easy to use and you can validate every aspect of the email you are intercepting.
It's a Java SMTP server implementation meant for unit testing. (Just make sure you redirect your email to the machine running dumbster...)
I just found another alternative that do almost the same: Greenmail
Greenmail also support POP3, IMAP with SSL so you can test your client against it.
For .NET I set the config file to deliver mail to a folder, then you can have the automated test inspect the directory and files.
<system.net>
<mailSettings>
<smtp deliveryMethod="SpecifiedPickupDirectory">
<specifiedPickupDirectory pickupDirectoryLocation="c:\pickupDirectory"/>
</smtp>
</mailSettings>
</system.net>
While searching for options I found the following that may be useful.
DevNullSmtp
Use a null SMTP server for testing
Fake SMTP Service
twisted examples/emailserver.tac
"The Wiser framework for unit testing mail"
I've heard of a few other developers moving from Dumbster to Wiser and have migrated my testing code as well. One of the Java components that I've worked on sends thousands of emails a day and I've written unit tests for the different email templates and scenarios using Dumbster and Wiser. I prefer Wiser.
Snips from the Wiser website (http://code.google.com/p/subethasmtp/wiki/Wiser):
Wiser is a smart replacement for Dumbster and is built on top of the SubEtha SMTP Java library which allows your Java application to receive SMTP mail with a simple, easy-to-understand API.
A good program for email testing is smtp4dev (Windows only).
It's a dummy SMTP server. Sits in the system tray and does not deliver the received messages. The received messages can be quickly viewed, saved and the source/structure inspected.
http://smtp4dev.codeplex.com/
http://skaraarslan.blogspot.com/2008/02/how-to-check-email-works-without-using.html
(this presumes you are using .net to send emails)
Given that you mention exim and postfix (which I'm taking to be some kind of unix stuff), this answer might not be as useful as it could be, but check out Neptune. It's a fake SMTP server designed for automated testing. If you've got a spare windows box floating around, you could put Neptune on that then configure your app to send "through" the Neptune server.
Exim can be configured to accept incoming mails but not deliver them. Look for the keywords queue_only and queue_only_file in the documentation.
I personally modify the e-mail addresses to test, I send them to a dummy account of mine, that way I can validate not only that they sent, but that they appear in the proper format.
At my office, we have a server that is set up to always send all incoming mail to one address, regardless of who it's actually addressed to. We just point all our testing environments at that server and watch the QA mailbox fill up. I don't know what server it is, but it's probably some open source thing someone found.
Sendmail has a Test Mode.
You just invoke sendmail with the -bt parameter. As an example:
/usr/lib/sendmail -bt -Ciu-testconfiguration.cf
Please be aware that in this method, Sendmail requires an special configuration on rewrite rules. You need to understand how Sendmail rewrites addresses in order to properly create a .cf file for Test Mode.
Edit: See this article: http://ussg.iu.edu/usail/mail/debugging/
After not beeing happy with the solutions I found, I ended up writing developmentSMTP, easy to use, 100% Java --> cross platform.
Supports writing emails to file, forwarding emails or simply printing them on stdout.
Post Hoc is a pure Java application that looks exactly like an SMTP server to the application you are testing, but it simply collects all the email messages and allows you to inspect them using a web interface.
Freely available at: Post Hoc GitHub Site
For more information: PostHoc: Testing Apps that Send Email
If you're looking to manually test that the email sends and that the email template has the right kind of html and css that you're expecting, then I would recommend maildev https://www.npmjs.com/package/maildev. You can install and run it as a node module and also as a docker container! I've found it extremely handy for basic sanity testing of emails.