Đặng Phương Nam

Sometime you do not want email to delivery outside for development purpose. This article will show you how to forward all mail to local user using rainloop, postfix, dovecot and nginx

I made this guide using Ubuntu 18.04, if you are using earlier release of Ubuntu you can also try it

First, install postfix, dovecot and postfix-prce

apt install vim postfix dovecot-imapd postfix-prce

Create new user call catchall (or what ever you want)

useradd -m catchall

Create password for new user (which use for loggin rainloop on future step)

passwd catchall

Install rainloop

cd /usr/share/nginx/html

mkdir rainloop

curl -sL https://repository.rainloop.net/installer.php | php

cd /var/www/html

ln -s /usr/share/nginx/html/rainloop

Configure dovecot

vim /etc/dovecot/conf.d/10-mail.conf

Replace mail_location as below

mail_location = maildir:/home/%u/Maildir

Configure Postfix

Change postfix config file

cd /etc/postfix

mv main.conf main.conf.org
mv main.conf.proto main.conf

Edit postfix config file

vim /etc/postfix/main.conf

uncomment

home_mailbox = Maildir/

uncomment

alias_maps = hash:/etc/aliases

then add aliases.regexp as below

alias_maps = hash:/etc/aliases, pcre:/etc/aliases.regexp

uncomment

alias_database = hash:/etc/aliases

Near the end of config file we will see some blank variable, please fill it like below

sendmail_path = /usr/sbin/sendmail.postfix
newaliases_path = /usr/bin/newaliases.postfix
mailq_path = /usr/bin/mailq.postfix
setgid_group = postdrop
html_directory = no
manpage_directory = /usr/share/man
## comment out
#sample_directory
readme_directory = /usr/share/doc/postfix-2.10.1/README.Debian

## add new line for transport_maps

transport_maps = pcre:/etc/postfix/transport_maps

Create aliases.regexp

vim /etc/aliases.regexp

add below content

/(?!^root$|^catchall$)^.*$/ catchall

create transport.db

if transport file does not available please create it or skip if it already in /etc/postfix

touch /etc/postfix/transport

then run

postmap /etc/postfix/transport

now create transport_maps file

vim /etc/postfix/transport_maps

add below content

/^.*@.*$/ local

Comment out some line from master.conf file

Please comment out all of below config

maildrop
uucp
ifmail
bsmtp
scalemail-backend
mailman

change postmaster to our user

vim /etc/aliases

change postmaster from root to catchall

postmaster: catchall

Create aliases.db

postalias /etc/aliases

Start service

service postfix start

service dovecot start

Configure Rainloop

Access http://yourip/rainloop/?admin

Default rainloop account and password is admin/12345

In domain tab, delete all domain from list and add new localhost domain like below image

Click Add button

In login tab, add default domain as localhost

now login to rainlop user by url http://yourip/rainloop

input email as: catchall

input password as you create at early step

Test sending email

echo "this is a test message" | mailx -s 'this is a test subject' [email protected]

Check your rainloop inbox to make sure you receive new email

if not, please check in mail log

tail -fn 100 /var/log/mail.log

if you see that all mail was send to root@localhost, do forward them

echo "root: catchall@localhost" >> /etc/aliases && newaliases

If you got command not found please install mailutils

apt install mailutils

Hope this help

If you have any problem, please leave me a line below