Dovecot: Secure IMAP Email Server February 2, 2006 Why Run An - - PowerPoint PPT Presentation

NDLUG

Dovecot: Secure IMAP Email Server

February 2, 2006

Why Run An Email Server?

• Control resource allocation

– Limited storage on regular email account (50 megabytes at ND) – Unlimited on your own computer

• Do filtering and sorting

– Spam filtering: Bogofilter (Bayesian Filter) – Sort mail into folders: Procmail

• Access email from everywhere
• Have a local mail archive
• It's freaking sweet

A Tale of Two Email Services

• POP3

– Ubiquitous – Download whole messages

from server to local machine

– Minimum use of connect

time

– Minimum use of server

resources

• IMAP

– Access inbox from different

machines

– Faster startup times (only

download headers)

– Messages remain on the

server

– Subscription Folders

General NIX Email Setup

1Fetchmail/Getmail queries pop email server 2Messages sent to procmail for sorting 3Bogofilter checks to see if emails are spam 4Messages are saved to local inbox ex: /home/user/mail

Dovecot Email Server

• POP and IMAP server
• Compatible with UW-IMAP

and Courier-IMAP

• Integration with

/etc/passwd

• Fast and efficient
• Fail safe
• TLS/SSL Support
• www.dovecot.org

Installation

• Ubuntu Linux

– sudo apt-get install dovecot-imapd (IMAP) – sudo apt-get install dovecot-pop3d (POP3)

• NetBSD

– cd /usr/pkgsrc/mail/dovecot; sudo make install clean

• Arch Linux

– sudo pacman -S dovecot

IMAP Configuration

dovecot.conf:

protocols = imaps # Use IMAPS Port ssl_disable = no # Enable SSL ssl_cert_file = /etc/ssl/certs/dovecot.pem # Server Certificate ssl_key_file = /etc/ssl/private/dovecot.pem # Server Key login = imap # Allow IMAP Login default_mail_env = mbox:/home/%u/mail:INBOX=/home/%u/mail/Inbox # Local mail location auth = default # Use default auth_mechanisms = plain # Use Plain Text Login auth_userdb = passwd # Use /etc/passwd auth_passdb = pam # Use PAM auth_user = root # Process Owner

Notes

• If you want to use SSL (i.e. IMAPS), you need to generate

your own SSL certificates

– Dovecot comes with a script mkcert.sh to aid this – You can reuse any certificates that you already have

• You can run Dovecot as a non-root user (AFS?)
• Both MBOX and Maildir mail format are supported (dbox

and possibly SQL DB in the future)

• SMTP is handled by another program: sendmail, msmtp
• RTFM or Wiki