One of the default applications I always install on Ubuntu is Postfix as an MTA. I find it very reliable, and along with Procmail is a good method for triggering jobs using inbound emails. However, I've never installed an end-to-end email solution - one where I could compose, view, and respond to emails from off the server. Recent changes to my current email provider has made me look at this option, and I now have a working solution. As with most all OSS there's if anything too much information out on the internet, and it's hard to find the wood.
Anyway, here is what I've done. Bear in mind that this is only for a 'personal' mail server ... not a corporate setup of 100s of users.
Dovecot
I installed Dovecot from the repositories - dovecot, dovecot-imap, and dovecot-pop3d.
Post-installation I amended my system users' mailbox format from mbox to maildir. This is quite straightforward as there was no mail I wanted to keep, so just building the ~/Maildir folders and adding them into /etc/skels was enough.
The configuration of Dovecot hardly needed any updates:
- changed 10-mail.conf to:
mail_location = maildir:~/Maildir
- changed 10-ssl.conf to:
ssl = yes
and I also created a separate log-file for dovecot in /var/log/dovecot.log with logrotation in /etc/logrotate.d
These changes meant I would be connecting to Dovecot via SSL and it would understand/expect Maildir format mail on the server.
Procmail
I already had Procmail running spamassassin, and some extra rules to intercept certain messages. Rather than replacing this with Sieve I kept these and just used the Dovecat LDA to deliver inbound mail to Maildir at the end of the existing rules.
Changes were limited to just:
MAILDIR=$HOME/Maildir/
DELIVER="/usr/lib/dovecot/deliver"
and -
as the last lines in .procmailrc (I use user-level procmailrc files)
Postfix
As Postfix was already delivering to Procmail, I still used it's virtual_hosts and virtual.db to point external email addresses to internal system users. No virtual users (within Dovecot) were used.
Delivering mail now delivered email to the correct users (as before) but I now had external access via POP3S and IMAPS routes.
Mail
The 'mail' command in the default install for Ubuntu doesn't understand Maildir format, so I installed heirloom-mailx to replace it. You also need to update a few pam modules to let some services know to go to Maildir and not mbox. I changed ssh -
session optional pam_mail.so dir=~/Maildir standard # [1]
and su -
session optional pam_mail.so dir=~/Maildir nopen
So the notices you receive at logon regarding mail look in the correct place, and when switching user you can view the new users mail correctly.
Logging
Postfix was (still) logging to /var/log/mail.log and Dovecot to /var/log/dovecot.log. IMAP/POP3 authentication was in /var/log/auth.log.
Roundcube
For a web front-end I decided to install Roundcube. The version in the repositories is quite old (v0.7) and much newer versions are available to download from myroundcube. I followed the installation procedure
(it's a little odd, but basically:
download gzip, de-compress and place somewhere your web server can access it;
create a mysql (for me anyway) database, and user, initialise with the SQL/initial.sql script
then point browser to the installer folder e.g. mymail/installer and follow instructions
)
This then enables you to logon to your email via this web interface using your system user/password.
Security
A couple of things worried me about this setup. One was that I don't use very string passwords for my system users (as I use a PKI for security and disallow password logon), and as you access over IMAP/POP3 from the localhost I didn't want to leave just any user exposed. There are a myriad of solutions to this, but I went for this.
Fail2ban
I left access as localhost, rather than the server's IP address (I might want to genuinely access via a real external server at some point) so the auth.log and dovecot.log are a bit useless as they'll just report localhost as the remote IP address. Regardless I still set up fail2ban for dovecot checking and banning. The fail2ban I have doesn't have IPv6 capability so I updated dovecot.conf to "listen = *" so it would only listen on IPv4 addresses, and I'd avoid spurious warnings from fail2ban whenever a logon failed.
I added a fail2ban jail for roundcube itself as it logs logon failures. The Roundcube log by default is in /var/lib/roundcube/logs/errors so I created a filter in /etc/fail2ban/filter.d as roundcube.conf -
#
failregex = .*(IMAP|POP3) Error: Login failed for .* from \..*
# Option: ignoreregex
# Notes.: regex to ignore. If this regex matches, the line is ignored.
# Values: TEXT
#
ignoreregex =
- as the error message looked like:
[17-Aug-2014 18:30:40 +0100]: IMAP Error: Login failed for xxxx from aa.bb.cc.dd AUTHENTICAT... etc.
Then just included this new jail in jail.local:
[roundcube]
enabled = true
port = http,https
filter = roundcube
logpath = /var/lib/roundcube/logs/errors
maxretry = 3
So this means I'll block genuine failures at the web end, even though the IMAP/POP3 routes are still exposed.
In addition, rather than let any system user logon via Dovecot I decided to create new system users just for email with strong passwords and then explicitly give Dovecot access to these users. So I amended the pam for Dovecot to add this line -
auth required pam_listfile.so item=user sense=allow file=/etc/dovecot/users onerr=fail
and then in /etc/dovecot/users have the list of users who I want to logon in this way. This means I'll not have anyone brute-force using Dovecot to hack the root password (if there was one) or any other users than those I explicitly allow.
Roundcube Changes
There are a few quirks with Roundcube which I didn't much like so made a few simple changes.
Paragraph Spacing
There are options in Roundcube to determine what sort of HTML 'brackets' a new paragraph. Some of these replace the <p> with <br /> but as in the Roundcube FAQ I agree that a genuine 'return' should create a new paragraph. This results in 1em gaps between paragraphs which is different to how most email clients show paragraph breaks.
To amend this update the 'skin' being used to add a p{margin:0} - I found this needed changing both in the editor-content.css (for writing mail) and in the styles.css (for previewing/showing email).
Default Fonts
Although you can set the default font in user settings, this sets the font displayed in the editor, not the font selected in the editor (which is TinyMCE). There's a good solution in this Stack Exchange post and the code just goes in js/editor.js -
(within definition of conf, line 30-ish, add)
setup : function(ed) {
ed.onInit.add(function(ed) {
ed.execCommand("fontName", false, "Arial");
ed.execCommand("fontSize", false, "2");
});
}
(I think there ought to be a way of extended the conf via the setting rcmail_editor_settings but haven't looked into this yet)
Email Replies
I don't like the indentation mechanism for replies. This leads to many indents and very narrow text on large conversations. I prefer to just give the original text and add to the top (like Outlook or Yahoo Mail) so I've changed the include of program/steps/mail/compose.inc:
(in rcmail_create_reply_body ... this probably doesn't show well, but you catch the drift!) -
// // build reply (quote content)
// $prefix = '<p>' . rcube::Q($prefix) . "</p>\n";
// $prefix .= '<blockquote>';
// if (intval($RCMAIL->config->get('reply_mode')) > 0) { // top-posting
// $prefix = '<br>' . $prefix;
// $suffix = '</blockquote>';
// }
// else {
// $suffix = '</blockquote><p></p>';
// }
$suffix = '';
$prefix = sprintf(
"<br /><p><hr/></p>" .
"<b>%s:</b> %s<br />" .
"<b>%s:</b> %s<br />" .
"<b>%s:</b> %s<br />" .
"<b>%s:</b> %s<br />" .
"<br />",
$RCMAIL->gettext('from'), rcube::Q($MESSAGE->get_header('from'), 'replace'),
$RCMAIL->gettext('to'), rcube::Q($MESSAGE->get_header('to'), 'replace'),
$RCMAIL->gettext('sent'), rcube::Q(format_date($MESSAGE->headers->date, $RCMAIL->config->get('date_long'))),
$RCMAIL->gettext('subject'), rcube::Q($MESSAGE->subject));
if ($cc = $MESSAGE->headers->get('cc'))
$prefix .= sprintf("<tr><th align=\"right\" nowrap=\"nowrap\" valign=\"baseline\">%s: </th><td>%s</td></tr>",
$RCMAIL->gettext('cc'), rcube::Q($cc, 'replace'));
if (($replyto = $MESSAGE->headers->get('reply-to')) && $replyto != $MESSAGE->get_header('from'))
$prefix .= sprintf("<tr><th align=\"right\" nowrap=\"nowrap\" valign=\"baseline\">%s: </th><td>%s</td></tr>",
$RCMAIL->gettext('replyto'), rcube::Q($replyto, 'replace'));
This creates replies that look like:
Here is a response to that message
From: Me
To: "you@yourplace.co.uk"
Sent: 18/08/2014 11:01
Subject: Testing to me
And that's just about it!
