Dev {Tricks}

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iRedMain Checklist

Backup old emails

zip -r archive-name.zip directory-name

Test the ZIPed File if it is Valid

unzip -t archive-name.zip

For more zip and unzip command click here.

Install iRedMail on Debian or Ubuntu Linux

System Requirements

To install iRedMail on Debian or Ubuntu Linux, you need:

    • A FRESH, working Debian/Ubuntu Linux. [Supported OS]
    • At least 4 GB memory is required for a low traffic production mail server with spam/virus scanning enabled..
    • Make sure 3 UID/GID are not used by other user/group: 2000, 2001, 2002.

Preparations

On Debian/Ubuntu Linux, hostname is set in two files: /etc/hostname and /etc/hosts.

  • For short hostname, not Fully Qualified Domain Name (FQDN). 
    vi /etc/hostname

    Short hostname example

    imail
  • Static table lookup for hostnames. 
    vi /etc/hosts

    Part of file: /etc/hosts

    127.0.0.1 mx.example.com mx localhost localhost.localdomain

    Warning: Please list the FQDN hostname as first item.

Verify the FQDN hostname.

hostname -f

If it wasn’t changed after updating above two files, please reboot server to make it work.

Update software repositories

sudo apt update

Install available software updates

sudo apt upgrade

Enable default official Debian/Ubuntu apt repositories

  • iRedMail needs official Debian/Ubuntu apt repositories, please enable them in /etc/apt/sources.list. 
    cat /etc/apt/sources.list

    Usually the repositories with the description main are the official supported repositories.

  • Install package gzip so that you can uncompress downloaded iRedMail package. 
    sudo apt-get install gzip

Download the latest release of iRedMail

  • Download page
  • Upload it to your root directory or run 
    wget https://github.com/iredmail/iRedMail/archive/1.6.2.tar.gz
  • Uncompress iRedMail tarball on root 
    tar zxf iRedMail-x.y.z.tar.gz

    Replace x.y.z by the real version number

Start iRedMail installer

cd /root/iRedMail-x.y.z/
bash iRedMail.sh

Welcome and thanks for your use >> Press Enter

Specify location to store all mailboxes. Default is /var/vmail/. >> Press Enter

Choose backend used to store mail accounts. You can manage mail accounts with iRedAdmin, our web-based iRedMail admin panel.

Note
There’s no big difference between available backends, so it’s strongly recommended to choose the one you’re familiar with for easier management and maintenance after installation.

If you choose to store mail accounts in OpenLDAP, iRedMail installer will ask to set the LDAP suffix.

To MySQL/MariaDB/PostgreSQL users

If you choose to store mail accounts in MySQL/MariaDB/PostgreSQL, iRedMail installer will generate a random, strong password for you. You can find it in file iRedMail.tips.

Add your first mail domain name

Set password of admin account of your first mail domain.

Note: This account is an admin account and a mail user. That means you can login to webmail and admin panel (iRedAdmin) with this account, login username is full email address.

Choose optional components

Which webmail should you choose? Roundcube or SOGo?

  • Roundcube is a fast and lightweight webmail.
  • SOGo offers webmail, calendar (CalDAV), contacts (CardDAV) and ActiveSync.
  • It’s ok to install both, but you can only manage mail filters with Roundcube in this case.

 

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Hardening Postfix For ISPConfig 3

Reverse DNS, (DNS PTR Record)

You can check your rdns with the command host:

host YOUE-IP

SPF For Your Domain (DNS TXT Record)

Copy the spf result, then go to ISPConfig -> dns -> zones ->click on your domain name -> click on records tab -> and click on TXT

Hostname -> example.com. (with dot at the end!)

Text -> Paste here the spf result

Example:

v=spf1 a mx ptr ip4:YOUR.IP.ADDRESS -all

Click on Save.

Postfix main.cf

Let’s add/change something to /etc/postfix/main.cf

Helo restrictions:

smtpd_helo_required = yes
smtpd_helo_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_non_fqdn_helo_hostname, reject_invalid_helo_hostname

Strict rfc:

strict_rfc821_envelopes = yes

Clients restrictions:

smtpd_client_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unknown_client_hostname, check_client_access mysql:/etc/postfix/mysql-virtual_client.cf

Recipient restrictions:

smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, check_recipient_access mysql:/etc/postfix/mysql-virtual_recipient.cf, reject_unknown_recipient_domain

Data restrictions:

smtpd_data_restrictions = reject_unauth_pipelining

Smtpd delay:

smtpd_delay_reject = yes

Reload postfix:

/etc/init.d/postfix reload

SPF Check For Postfix (Debian And Ubuntu)

Intstall spf package:

apt-get install postfix-policyd-spf-python

or

apt-get install postfix-policyd-spf-perl

Add this to /etc/postfix/main.cf :

policy-spf_time_limit = 3600s

and add check_policy_service unix:private/policy-spf at the end of smtpd_recipient_restrictions:

smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, check_recipient_access mysql:/etc/postfix/mysql-virtual_recipient.cf, reject_unauth_destination, reject_unknown_recipient_domain, check_policy_service unix:private/policy-spf

Now edit master.cf and add at the end this (for the python version):

policy-spf unix – n n – – spawn
user=nobody argv=/usr/bin/policyd-spf

or this for the perl version:

policy-spf unix – n n – – spawn
user=nobody argv=/usr/sbin/postfix-policyd-spf-perl

…reload postfix.

/etc/init.d/postfix reload

Greylist

Greylisting is a method of defending email users against spam. A mail transfer agent (MTA) using greylisting will “temporarily reject” any email from a sender it does not recognize. If the mail is legitimate the originating server will, after a delay, try again and, if sufficient time has elapsed, the email will be accepted.

Installing postgrey (Debian, Ubuntu):

apt-get install postgrey

The configuration options are in /etc/default/postgrey ( default delay is 5 min).

Edit main.cf and add check_policy_service inet:127.0.0.1:10023 to the end of smtpd_recipient_restrictions:

smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, check_recipient_access mysql:/etc/postfix/mysql-virtual_recipient.cf, reject_unauth_destination, reject_unknown_recipient_domain, check_policy_service unix:private/policy-spf,check_policy_service inet:127.0.0.1:10023

…reload postfix:

/etc/init.d/postfix reload

DNSBL (DNS Based Blacklist/Blocklist)

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ISPConfig Checklist

How to install ISPConfig 3

How to Update ISPConfig 3

Update Instructions

To install the latest ISPConfig update, run this command on the shell of the server as root user:

ispconfig_update.sh

The ISPConfig updater will then check for new releases and guide you through the update process.
A detailed update guide is available here

 

 

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Limit text lines of a div using CSS

<div class=”text-line-3″>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aliquam consectetur venenatis blandit. Praesent vehicula, libero non pretium vulputate, lacus arcu facilisis lectus, sed feugiat tellus nulla eu dolor. Nulla porta bibendum lectus quis euismod. Aliquam volutpat ultricies porttitor. Cras risus nisi, accumsan vel cursus ut, sollicitudin vitae dolor. Fusce scelerisque eleifend lectus in bibendum. Suspendisse lacinia egestas felis.</div>

.text-line-3 {
overflow: hidden;
text-overflow: ellipsis;
display: -webkit-box;
-webkit-line-clamp: 2; /* number of lines to show */
line-clamp: 2; 
-webkit-box-orient: vertical;
}

 

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How to increase Google Scholar citation count?

Steps to increase Google Scholar citation count

  1. Scope of the article
    • Immediate impact on society.
    • Solve practical problems.
    • Overcome the challenges.
    • Introduce new technology.
  2. Linking evidence to the paper
    • Provide links to the supporting evidence.
    • Add relevant links in the references of a research paper.
  3. Keyword Selection
    • Select at least 4 keywords.
    • Repeat keywords throughout the paper including in the abstract, introduction, body, and conclusion.
  4. Title
    • Short and descriptive. Should be around 60 words, including the keyword related to the topic.
  5. Headings
    • Divide paper into a good number of paragraphs under proper headings. These headings should include keywords.
  6. Abstract
    • Include at least 4 to 6 keywords.
  7. Accessibility
    • Publish the paper in an open-access journal (OJS).
    • If ojs is not possible, post in a repository (DSpace).
    • Share widely. Twitter, Facebook, Instagram, etc.
  8. Self-citation
    • Can cite previous relevant and related papers in the present paper.
  9. Inclusion of tables and figures
    • Reliable graphical data like tables, figures, and a graphical abstract.
  10. Promotion of research papers
    • Promote work(s) among other scholars. Such scholarly websites are Science Direct, Research Gate, Kudos, etc.
  11. Collaboration with fellow authors
  12. Quality of the research paper
  13. Reusability
    • Revolving around the main idea. Other researchers can create another new piece of work.
  14. Original and effective
    • An original idea is effective. The paper should have experiments that are done practically with actual results.