Yes, We will run the command [sudo apt-get install postfix].
To ensure you will get the newest version, you have to run below first.
You will see some log like below.
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
libgnutls-dane0 libunbound8
Use 'sudo apt autoremove' to remove them.
Suggested packages:
procmail postfix-mysql postfix-pgsql postfix-ldap postfix-pcre postfix-lmdb postfix-sqlite sasl2-bin | dovecot-common libsasl2-modules
| dovecot-common postfix-cdb ufw postfix-doc
The following packages will be REMOVED:
exim4-base exim4-config exim4-daemon-light
The following NEW packages will be installed:
postfix
0 upgraded, 1 newly installed, 3 to remove and 0 not upgraded.
Need to get 1,412 kB of archives.
After this operation, 62.5 kB disk space will be freed.
Do you want to continue? [Y/n] y
Get:1 http://ftp.udx.icscoe.jp/Linux/raspbian/raspbian buster/main armhf postfix armhf 3.4.23-0+deb10u1 [1,412 kB]
Fetched 1,412 kB in 2s (774 kB/s)
Preconfiguring packages ...
(Reading database ... 221744 files and directories currently installed.)
Removing exim4-daemon-light (4.92-8+deb10u7) ...
Removing exim4-base (4.92-8+deb10u7) ...
Removing exim4-config (4.92-8+deb10u7) ...
Selecting previously unselected package postfix.
(Reading database ... 221611 files and directories currently installed.)
Preparing to unpack .../postfix_3.4.23-0+deb10u1_armhf.deb ...
Unpacking postfix (3.4.23-0+deb10u1) ...
Setting up postfix (3.4.23-0+deb10u1) ...
Adding group `postfix' (GID 126) ...
Done.
Adding system user `postfix' (UID 118) ...
Adding new user `postfix' (UID 118) with group `postfix' ...
Not creating home directory `/var/spool/postfix'.
Creating /etc/postfix/dynamicmaps.cf
Adding group `postdrop' (GID 127) ...
Done.
setting myhostname: raspberrypi
setting alias maps
setting alias database
changing /etc/mailname to achillia-mfg.com
setting myorigin
setting destinations: achillia-mfg.com, $myhostname, raspberrypi, localhost.localdomain, localhost
setting relayhost: smtp.localhost
setting mynetworks: 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
setting mailbox_size_limit: 0
setting recipient_delimiter: +
setting inet_interfaces: all
setting inet_protocols: all
WARNING: /etc/aliases exists, but does not have a root alias.
Postfix (main.cf) is now set up with a default configuration. If you need to
make changes, edit /etc/postfix/main.cf (and others) as needed. To view
Postfix configuration values, see postconf(1).
After modifying main.cf, be sure to run 'service postfix reload'.
Running newaliases
Created symlink /etc/systemd/system/multi-user.target.wants/postfix.service → /lib/systemd/system/postfix.service.
Processing triggers for systemd (241-7~deb10u8+rpi1) ...
Processing triggers for man-db (2.8.5-2) ...
Processing triggers for rsyslog (8.1901.0-1+deb10u2) ...