Click here for "Error Codes for Commercial Air Conditioners".

Debian10.13 ; Antivirus , Mail Server

1.Anti-virus Clamav installed

1.1 Install

The clamav-related configuration files are installed in the /etc/clamav/ folder.

1.2 Virus definition updates

If the virus definitions can be updated with the above command, but the following error occurs, change the log settings and run the command again.
ERROR: /var/log/clamav/freshclam.log is locked by another process
ERROR: Problem with internal logger (UpdateLogFile = /var/log/clamav/freshclam.log).

⚫Change configuration file

1.3 Virus Check Confirmation

①Running manual virus checks

Infected files: 0 No virus.

②Virus detection by downloading test viruses
Download a harmless virus and test it for detection.
Log in as a general user and check

Thus, the virus is notified with the indication "FOUND" and "Infected files: 1".
Also, the "--remove" option was added, so the test virus was removed.

1.4 Create a script file to do a full scan

①Contents of (new)

②execute authorization

③Create a folder for virus quarantine (if it already exists, it is OK, but if it does not, a runtime error will occur because it is specified as an excluded directory in the above script).

④Running it.

⑤Scheduled virus scan execution with cron

2. Email software installation

2.1 Postfix : Installation/Configuration

Install Postfix and build an SMTP server; SMTP uses 25/TCP.
To prevent unauthorized mail relay, use the SASL function of Dovecot, described below, and configure Postfix so that authentication is also required for sending mail.


Installation Status Screen
You will be asked to select a general configuration setting, select "No Configuration" to set it manually later.

②Configuration File Editing

Editorial content

③ edit

Editorial content

④Reflection of settings

2.2 Dovecot : Installation/Configuration

Install Dovecot and build a POP/IMAP server, using 110/TCP for POP and 143/TCP for IMAP
①Configure Dovecot to provide SASL functionality for Postfix

②Setting Reflection

2.3 Email User Account Registration

Register a user account for e-mail.
This is a setting for when a user account on the OS is also used for e-mail.
If you want to use mail with a user account on the OS, no additional configuration is required, just register the OS user

①Mail client installation

②Mailboxes are set to refer to Maildir

2.4 Open ports

2.5 operation check ①

①Send test mail to yourself [mail (user name)@(host name)].
username : huong

Ctrl + D key to end a statement

Check incoming mail

2.6 operation check ②

Set up and confirm your account in Mozilla Thunderbird
①Start Thunderbird, and click "Tools", "Account Settings".

②「Account Actions」「Add Mail Account」

③Your full name : any name
Email addtess :
Password : Password for huong
Click on "Configure manually"

④Set "INCOMMING SERVER" and "OUTGOING SERVER" as shown below and click "Re-test".

⑤「The following settings were found by probinfg the given server」

After clicking "Done", the following "Warning" appears, but there is no problem, so click "Confirm".

⑥"Account syccessfuly created" is displayed and click "Finish".

3 Applied ClamAV to mail server Postfix

Set up Postfix and Clamav to work together to scan incoming and outgoing mail in real time.

①Install Amavisd and Clamav Daemon and start Clamav Daemon

If the server does not use a fully qualified domain name (FQDN) as the host name, Amavis may fail to start.
Also, since the OS hostname may change, set a valid hostname directly in the Amavis configuration file

②15-content_filter_mode edit

③Register your own domain name

④ edit

⑤ edit

Editorial content
# Add all the following lines to the last line

⑥Configuration Reflection

⑦When you send an e-mail to yourself on Thuderbird, etc., it is successful if you see the following message in the header of the incoming e-mail.

4 Applied spamassassin to mail server Postfix

4.1 Install spamassassin


②SpamAssassin Settings
The configuration file is "/etc/mail/spamassassin/".

Use default without additional settings
Create Maildir for storing spam mails
Create a directory in Maildir format to store spam emails
Create a directory ".Spam" in Maildir format for storing spam mails.
Creation is done by the target user.

4.2 Procmail Preparation

①Install Procmail

If installed, the following results are returned

②Procmail Settings
If you put it in "/etc/procmailrc", which is in charge of the entire mail filter, it will be applied to all users.
The filter will be applied only to that user if it is written in "/home/username/.procmailrc", which is a mail filter file for each user.
This time, to apply to all users, we will write in "/etc/procmailrc".

procmailrc description (newly created)

4.3 Postfix Configuration

① Edit

②Reflecting and activating settings

4.4 Spam Email Learning

Allows all users to learn the entire contents of their ".Spam" directory as spam mail
①Spam Email Learning

②Normal mail learning

③Create a script and register it with Cron
Name the file "" and place it under /opt/script/.
After saving the script, give it executable access as "chmod 750". Contents

Once is created, create a definition file directly under /lib/systemd/system. The name should end in .service, such as spam-learns.service.
Type is defined by simple

Contents of spam-learns.service

④If you send an e-mail to yourself in Thunderbird with the following information in the body, the following will appear in the header.

Copied title and URL