Raspberrypi.mail

Konzept

Internet     |   Raspi 
             |
:25 (smtp)   ->  [ Postfix ] -> Filesystem "/var/mail/user"
             |               -> dovecot User API 
             |
:110 (pop3)  ->  [ dovecot ] -> Filesystem "/var/mail/user"
             |               -> Linux User API

• Mein Ziel ist ein ordentlicher eigenständiger Mailserver (er braucht keinen anderen Mailserver zum versenden der Mail)
• Es soll keine Datenbank nötig sein
• Mail-Accounts sind native Linux-User, über den Kernel läuft somit auch die Authentifizierung
• Mail-Speicherung erfolgt im mbox Format in /var/mail so wie das Linux vorsieht
• eMail-Adressen sind in der Text-Datei "/etc/postfix/virtual" aufgelistet

Vorarbeiten

benötigte Software

apt-get install dovecot-pop3d postfix

Ordentlich starten

• postfix ist von dovecot abhängig, deshalb sollte postfix erst starten wenn dovecot schon Aktiv ist

erst dovecot

joe /lib/systemd/system/dovecot.service

[Unit]
Requires=network-online.target
After=network-online.target

dann postfix

joe /lib/systemd/system/postfix.service

[Unit]
Requires=dovecot.service
After=network-online.target nss-lookup.target dovecot.service

Dienst beim Reboot starten

systemctl enable dovecot
systemctl enable postfix

Test

noch zu klären ...

Im Moment gibt es noch Datei-Rechte Probleme, dies ist ein Workaround so dass beide Programme miteinander arbeiten können

chmod 777 /var/mail

drwxrwsrwx  2 root mail       4096 Feb 14 11:41 mail

postfix

http://www.postfix.org/features.html

main.cf

virtual_alias_maps = hash:/etc/postfix/virtual
smtpd_sasl_auth_enable = yes
smtpd_sasl_type = dovecot

Test

• https://www.thomas-krenn.com/de/wiki/TCP_Port_25_(smtp)_Zugriff_mit_telnet_%C3%BCberpr%C3%BCfen
• https://www.ndchost.com/wiki/mail/test-smtp-auth-telnet

dovecot

Information

https://dovecot.org/

Installation

apt-get install dovecot-pop3d

Konfiguration

/etc/dovecot/conf.d/10-ssl.conf

##
## SSL settings 
##

# SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>
ssl = no

# PEM encoded X.509 SSL/TLS certificate and private key. They're opened before
# dropping root privileges, so keep the key file unreadable by anyone but
# root. Included doc/mkcert.sh can be used to easily generate self-signed
# certificate, just make sure to update the domains in dovecot-openssl.cnf
#ssl_cert = </etc/dovecot/dovecot.pem
#ssl_key = </etc/dovecot/private/dovecot.pem

# If key file is password protected, give the password here. Alternatively
# give it when starting dovecot with -p parameter. Since this file is often
# world-readable, you may want to place this setting instead to a different
# root owned 0600 file by using ssl_key_password = <path.
#ssl_key_password =

# PEM encoded trusted certificate authority. Set this only if you intend to use
# ssl_verify_client_cert=yes. The file should contain the CA certificate(s)
# followed by the matching CRL(s). (e.g. ssl_ca = </etc/ssl/certs/ca.pem)
#ssl_ca = 

# Require that CRL check succeeds for client certificates.
#ssl_require_crl = yes

# Directory and/or file for trusted SSL CA certificates. These are used only
# when Dovecot needs to act as an SSL client (e.g. imapc backend). The
# directory is usually /etc/ssl/certs in Debian-based systems and the file is
# /etc/pki/tls/cert.pem in RedHat-based systems.
#ssl_client_ca_dir =
#ssl_client_ca_file =

# Request client to send a certificate. If you also want to require it, set
# auth_ssl_require_client_cert=yes in auth section.
#ssl_verify_client_cert = no

# Which field from certificate to use for username. commonName and
# x500UniqueIdentifier are the usual choices. You'll also need to set
# auth_ssl_username_from_cert=yes.
#ssl_cert_username_field = commonName

# DH parameters length to use.
#ssl_dh_parameters_length = 1024

# SSL protocols to use
#ssl_protocols = !SSLv3

# SSL ciphers to use
#ssl_cipher_list = ALL:!LOW:!SSLv2:!EXP:!aNULL

# Prefer the server's order of ciphers over client's.
#ssl_prefer_server_ciphers = no

# SSL crypto device to use, for valid values run "openssl engine"
#ssl_crypto_device =

# SSL extra options. Currently supported options are:
#   no_compression - Disable compression.
#ssl_options =

Test

• https://blog.yimingliu.com/2009/01/23/testing-a-pop3-server-via-telnet-or-openssl/

eMail-Konten anlegen

eMail.sh

./eMail.sh user password

#
# create a Postfix Mail Account
#

useradd --gid postfix --create-home --shell /bin/false $1
echo "$1:$2" | chpasswd
chmod 777 /home/$1
touch /var/mail/$1
chown $1 /var/mail/$1
chgrp postfix /var/mail/$1
chmod 0660 /var/mail/$1

offene Probleme

• Wenn ein neuer User angelegt wird und erstmalig mit dovecot per pop3 angefragt wird schafft dovecot es nicht eine leere mbox anzulegen
• Wenn ein neuer user angelegt wird schafft es postfix eine neue mbox anzulegen, diese kann aber Rechtmäßig nicht von dovecot gelesen werden
• dovecot will imap Sachen machen, obwohl ich nur pop3 einsetze.
• dovecort schafft es nicht im home des users das Verzeichnis .imap anzulegen (rechteproblem)

Sep 25 20:30:38 pi3x04 dovecot: pop3(mail-ma1): Error: mkdir_parents(/home/mail-ma1/.imap/INBOX) failed: Permission denied

-> Versuch

#
# die User einfach mal der Gruppe "mail" zuordnen, nicht postfix, das war dumm
#
mail:x:8:8:mail:/var/mail:/usr/sbin/nologin