Postfix, Dovecot, SMTP (07.02.2021)#
Postfix virtual users#
Config vi /etc/postfix/main.cfvirtual_mailbox_maps = hash:/etc/postfix/vmailbox <= all mailboxes and locations virtual_alias_maps = hash:/etc/postfix/virtual <= only for forwarding, mailboxes not needed here, too
If you want to use a local mail client (POP3/IMAP), you need to use Dovecot additionally to handle this. Mailbox locations according to dovecot at vi /etc/dovecot/conf.d/10-mail.conf
mail_location = mbox:~/mail:INBOX=/var/mail/vhosts/inetone/%uAuthentication and ports at vi /etc/dovecot/conf.d/10-master.conf
service pop3-login [ ... }
service auth { unix_listener auth-userdb {...} }
Authentication Driver 10-auth.conf > vi /etc/dovecot/conf.d/auth-system.conf.ext
passdb { ... }
userdb { ... }
After configure dovecot main.cf or master.cf do
service dovecot restart
After configure postfix
vi /etc/postfix/main.cf vi /etc/postfix/vmailbox vi /etc/postfix/virtual postmap /etc/postfix/vmailbox <= recreate db file postmap /etc/postfix/virtual <= recreate db file postfix reload <= reload config
Postfix and dovecot logging
vi /var/log/mail.log <= show log cp /dev/null /var/log/mail.log <= clean up logNote there are also mail.info, mail.warn and mail.err file, but mail.log contains all!
New email#
vi /etc/postfix/vmailbox <= add mail and mailbox location, will be at <virtual_mailbox_base> + location specified postmap /etc/postfix/vmailbox <= recreate db file postfix reload <= reload configPostfix does not need a local user or home folder for an email account, but dovecot needs them, if you use PAM:
useradd <username> <= create user passwd <username> <= set password mkdir /home/markus.ebel <= create home folder chown markus.ebel /home/markus.ebel <= change home folder owner chgrp markus.ebel /home/markus.ebel <= change home folder group
SMTP setup#
vi /etc/postfix/master.cfand enable
smtps inet n - y - - smtpd -o syslog_name=postfix/smtps -o smtpd_tls_wrappermode=yes -o smtpd_sasl_auth_enable=yes # -o smtpd_reject_unlisted_recipient=no # -o smtpd_client_restrictions=$mua_client_restrictions # -o smtpd_helo_restrictions=$mua_helo_restrictions # -o smtpd_sender_restrictions=$mua_sender_restrictions -o smtpd_recipient_restrictions= -o smtpd_relay_restrictions=permit_sasl_authenticated,reject # -o milter_macro_daemon_name=ORIGINATING -o smtpd_recipient_restrictions=permit_mynetworks,permit_sasl_authenticated,reject -o smtpd_sasl_type=dovecot -o smtpd_sasl_path=private/auth
SMTP setup error#
warning: SASL: Connect to private/auth failed: No such file or directory fatal: no SASL authentication mechanismsSolution: vi /etc/dovecot/conf.d/10-master.conf and enable
# Postfix smtp-auth
unix_listener /var/spool/postfix/private/auth {
mode = 0666
}
Notes:
- after this file /var/spool/postfix/private/auth gets created automatically
- you do not need to open a port like 465
Mailserver with postfix and dovecot (29.12.2020)#
based on grund-wissen.de
Install with apt-get install postfix
Start reconfigure wizard with sudo dpkg-reconfigure postfix
Configuration
vi /etc/postfix/main.cfexample at vi /usr/share/postfix/main.cf.dist
list config settings with postconf -d
Check and restart
postfix check sudo systemctl reload postfix service postfix reload service postfix restart <==
vi /etc/aliases
Dovecot #
„Mail Delivery Agent“ (MDA) for POP3 and IMAP.based on tecadmin.net
apt-get install dovecot-core dovecot-lmtpd dovecot-imapd dovecot-pop3d apt-get install dovecot-sieve dovecot-solr dovecot-antispam
vi /etc/dovecot/dovecot.conf /etc/dovecot/conf.d sudo systemctl enable dovecot.service sudo systemctl start dovecot.service sudo systemctl stop dovecot.service sudo systemctl status dovecot.service
Adding users (03.02.2019)#
You can use any system account
adduser usernameNote: to read those local emails in Linux check file /var/mail/<username>
or use command "mail", to be installed with "apt-get install mailutils".
or
Virtual Domain at /etc/postfix/virtual
1. You should have a virtual domain, exclude this at "mydestination", see Postfix
guide
vi /etc/postfix/main.cf
virtual_alias_domains = example.com, example2.com, ...
virtual_alias_maps = hash:/etc/postfix/virtual
2. create a addresses file (/etc/postfix/virtual)
vi /etc/postfix/virtual
postmaster@example.com postmaster
info@example.com joe
sales@example.com jane
# Uncomment entry below to implement a catch-all address
# @example.com jim
...virtual aliases for more domains...
postmap /etc/postfix/virtual
postmap /etc/postfix/vmailbox
postfix reload
postfix stop
postfix start
newaliases
service postfix restart
postsuper -d ALL <= delete all mails in queue
vi /var/log/mail.log
grep postfix /var/log/syslog
Virtual alias Domain vs virtual mailbox domain#
Virtual alias domains are not to be confused with the virtual mailbox domains that are implemented with the Postfix virtual(8) mail delivery agent. With virtual mailbox domains, each recipient address can have its own mailbox. With a virtual alias domain, the virtual domain has its own user name space.
vi /etc/postfix/main.cf
virtual_mailbox_domains = example.com
virtual_mailbox_base = /var/mail/vhosts <= base folder fo all mailboxes
virtual_mailbox_maps = hash:/etc/postfix/vmailbox <= subdirectories per mailbox
virtual_minimum_uid = 100 <= for safety
virtual_uid_maps = static:5000 <= system user for all emails
virtual_gid_maps = static:5000 <= system group for all emails
virtual_alias_maps = hash:/etc/postfix/virtual <= email addresses
vi /etc/postfix/vmailbox <= assigned folders for each email
info@example.com example.com/info
sales@example.com example.com/sales/
# Comment out the entry below to implement a catch-all.
# @example.com example.com/catchall
/etc/postfix/virtual:
postmaster@example.com postmaster
Pop3 / IMAP#
to betested:- Postfix is able to deliver POP3, then each mail address need to be mapped to a linux user for a proper password
- for IMAP you should use dovecot
Forward email with Postfix (Mailserver)#
Postfix is a mail server and it is used to forward mails to username@your-domain.de to any external account.
(Hint: It does not matter, if your-domain.de is a redirection to any other server like euve1234.vserver.de)
The postfix setup is described here,
but I had to modify it a little:
1. Installation
> su > apt-get update > apt-get install postfix > postfix reload2. Check
> postfix check > nmap localhost -p 25 > telnet localhost 25 > postconf -d > tail /var/log/mail.log
- If nmap does not work, then install it first
> apt-get install nmap3. Configure Postfix
vi /etc/postfix/main.cf
- Add/replace at the top
myorigin=your-domain.de myhostname=your-domain.de relay_domains=your-domain.de
- Extend
mydestination = your-domain.de, ... mynetworks = 5.45.105.135/8 ...
Disable
# myorigin = /etc/mailname
- Add/replace regarding SPAM rejection
# anti-spam: smtp restrictions
smtpd_recipient_restrictions = reject_invalid_hostname,
reject_unknown_recipient_domain,
reject_unauth_destination,
reject_rbl_client sbl.spamhaus.org,
permit
smtpd_helo_restrictions = reject_invalid_helo_hostname,
reject_non_fqdn_helo_hostname,
reject_unknown_helo_hostname
smtpd_client_restrictions = reject_rbl_client dnsbl.sorbs.net
- Open Port 25 for the outside world
inet_interfaces = all
- Save/Close main.cf and restart postfix (shell)
> service postfix restart
4. Setup email users
- Edit /etc/aliases
# This means that anyuser@your-domain.de will be forwarded to mailuser@mailprovider.de anyuser: mailuser@mailprovider.deHint: You should setup at least following email addresses
- webmaster@<your-domain>
- postmaster@<your-domain>
- abuse@<your-domain>
- Enter in shell:
> postconf -e "alias_maps=hash:/etc/aliases" > newaliases > postfix reload [or service postfix restart]