Configuring Fetchmail -> Postfix -> Cyrus -> IMAP

A nightmare over several days. I had set my mind that a local store was no good, because I needed to be able to access my email from outside the apartment, and decided that IMAP would be the way to go.

Technically, what I needed to do was to take the mail I got from my outside provider and download it to my server (this one). Then I needed to pass that email to an IMAP server, finally to get to it from the outside world. This seems stupid at first, but I run a dozen filters on my email, so that it makes very little sense for me to access the email directly on my ISP’s site.

I set my mind on the following flow (that pretty much was determined by the way SuSE does things):

1. fetchmail would download the email from the ISP in a cron job
2. postfix would deliver said email on
3. cyrus-imapd would make it available

As mentioned, after a few days everything started running smoothly – but initially it was quite the ordeal.

Fetchmail

Fetchmail configuration was pretty straightforward. That’s probably because I have done it before; but even where not, you really need to know only one thing in addition to the mailbox credentials: the syntax of the configuration file.

Check the files /etc/fetchmailrc or ~/.fetchmailrc (as root). There you probably will already find a line that looks like this:

poll “server.domain.com” protocol AUTO : user “john” there with password “pwd” is “smith” here ;

The only thing you need to watch out for is that the remote user and password match what you enter when you check email on the remote server. The here account (“smith” in the example) is the local user you would like email delivered to.

Once you have written the file, use cron to check for email on a regular basis. Check the man page, or simply follow these exact steps:

1. type ‘crontab -e’
2. type ‘i’ (for insert)
3. type ‘* * * * * fetchmail’
4. hit Escape
5. type ‘:wq’

That’s five stars in the fetchmail line. If you are not familiar with UNIX, you probably have no idea what you just did, but that really doesn’t matter.

Postfix

Admittedly, Postfix was the worst of it all. I managed to disconnect both fetchmail and cyrus from it, and to send my whole email system into a deep, deep tailspin. Finally, I understood a little more, and I decided it would make so much more sense if configuration files in UNIX were structured better, instead of being endless lists of argument/value pairs.

Let’s make it short: you will have to modify two files:

• /etc/postfix/master.cf
• /etc/postfix/main.cf

(One could question the wisdom of calling one file ‘master’, the other ‘main’ – which one’s the real master, which one the real main?)

Again, regardless. All you need to do here is make sure the last line with ‘mailbox_transport’ in main.cf says ‘cyrus’. Then you go to master.cf and make sure the line that says ‘cyrus’ in not commented out.

Ok, this is not really for beginners. But there is a really good intro in the documentation. Look for it under /usr/share/doc. Now restart the server by issuing ‘/etc/init.d/postfix reload’, and you are ready to go.

Cyrus

This should have been the most painful of the three, but it really was. 🙂

You start with the usual ‘apt-get install cyrus-imapd’. You will need to install ‘cyrus-imapd-utils’, too, otherwise you can’t create the mailboxes.

Once everything is running, check the status of the server or just start it like this: ‘/etc/init.d/cyrus-imapd start’

Now everything should be fine. Except that you need to create your mailbox. To do so, you first have to assign a password to the user ‘cyrus’. (For which you probably need no help). Then you log on to the administration tool: ‘cyradm -u cyrus localhost’

Ignore the prompt and type: ‘cm user.foo’. That’s short for create mailbox for user foo. Of course, you’d change foo to something else if you wanted a different user name.

That’s it!