Emails are the primary mode of official communication for any business establishment. As malicious actors keep gaining strength with sophistication, it becomes a high priority for organizations to do everything possible for their mail server protection to mitigate unpalatable outcomes.
With the advent of the ubiquitous smartphone, the way things work has transformed completely. Professional services have become a click-a-button activity and communication, an email away.
However, amidst this sophistication lies the unseen danger of malicious actors and phishing agents sharpening their swords to strike. Their only aim is to disrupt the systems and the network and steal as much information as possible.
With the introduction and usage of Office 365 and Google Workspace, the digital landscape has widened for more concerted and concentrated attacks. Hence, users must protect their systems from prying eyes in 2021, and the best place, to begin with, is the mail server.
In this blog post we are going to dive into the following topics:
- What is a Mail Server?
- Why Should Organizations Care about Mail Server Protection?
- How Should a Mail Server Be Protected?
- Best Practices For Mail Server Protection
- The Consequences Of Not Following The Best Practices For Mail Server Protection
- How Do Mail Admins Benefit From Following The Best Practices For Mail Server Protection?
Email has always been one of the most preferred modes of communication. At the end of 2019, the number of email users was 3.9 billion, and it is expected to grow by 3% each year.
The statistics of 2019 reveal that approximately 294 billion emails were sent and received each day. At such a furious rate, it can only be imagined how high this mode of communication would reach in the coming years, and with it, the cyber threats.
Hence, it becomes inevitable for all users to keep mail servers protected from the prying eyes of malicious actors.
What Is A Mail Server?
One could imagine a mail server to be a friendly postman. Every time a user sends an email, it passes through a series of mail servers before reaching its final recipient.
It may look almost instantaneous to the sender, but the entire process is a series of complex transfers and security checks. A world without mail servers would be devoid of most of the emails since only known addresses would be allowed as recipients for security reasons.
Mail servers can be split up into two main categories: outgoing mail servers and incoming mail servers.
Outgoing mail servers are known as SMTP, or Simple Mail Transfer Protocol, servers while incoming mail servers come in two main varieties.
POP3 or Post Office Protocol version 3 servers are best known for storing sent and received messages on one’s local hard drives. IMAP, or Internet Message Access Protocol, servers always store copies of messages on servers.
Why Should Organizations Care About Mail Server Protection?
The biggest reason organizations must care about mail server protection is that 90% of all vicious digital attacks on any individual or organization begin with a harmless-looking email sent to one of the email IDs.
It is not hard to imagine, given the figures related to the number of emails an average person sends or receives. The probabilities are high that at least one of the emails in a heap would be a malicious one.
Phishing through an email is the most common way malicious actors gain access to a secured network. Hence, it becomes imperative that the mail server requires all the protection it needs and in the best possible way.
If your enterprise relies on Gmail, Outlook, etc., you may not be focusing on mail server protection, but if you decide to implement and maintain your own mail server you need to protect them from spam, phishing, ransomware, and other email-borne threats.
This will help you provide full control of your enterprise email security, and how your emails are accessed, managed and stored.
How Should A Mail Server Be Protected?
Here are some basic steps to protect the mail server:
- Set up the mail relay option and define which IP addresses and domains will be allowed to relay the emails. It is done to avoid a scenario of it becoming an open relay, allowing your server to spam someone else’s inbox.
- Implement Sender Policy Framework (SPF), a TXT record of all the IP addresses authorized to send emails to the domain.
- Implement DKIM (Domain Keys Identified Mail), an email security standard and an email authentication protocol in the form of a TXT record. DKIM uses encryption and Public Key Cryptography to ensure message integrity. It uses hashing to validate the emails originating from trusted sources before allowing them to reach the domain.
- Implement DMARC (Domain-based Message Authentication, Reporting, & Conformance). It uses both SPF and DKIM to ensure more excellent protection by the authentication of messages.
- Usage of reverse DNS to block malicious users. The process of reverse resolving an IP address uses PTR records
- Usage of blocklists like Abusix Mail Intelligence, namely DNSBL (Domain Name System Blacklist) or RBL (Realtime Blackhole List) ensures that a more significant number of malicious IP addresses and domain names are blocked and archived.
- Usage of TLS or Transport Layer Security, another security protocol whose responsibility is to secure messages in transit and prevent them from being read.
Best Practices For Mail Server Protection:
One must follow the best practices listed below to protect the mail server from malicious attacks. It will prevent unwarranted access.
- Using password management best practices, such as using strong passwords, not repeating the same password, using password manager, etc., is a primary step to protect mail servers. Malicious actors can break weak passwords in no time as they use sophisticated software to guess the passwords.
- Enabling dynamic screening can help detect suspicious activities easily. Making too many attempts in a short time or sending many requests will be quickly noted.
- Enabling notification for account hijacking can know in time if a malicious actor has compromised the account and is using the credentials to send out emails to others to meet their illegitimate objectives.
- Data privacy is of prime concern and personally identifiable information or PII needs to be secured by enabling SSL/TLS.
- It is recommended that local email addresses be never whitelisted. Whitelisting allows messages to bypass security, and that may cause issues later.
- Always upgrade virus and spam protection for the network and the system. Older systems need constant monitoring and up-gradation to keep them safe from malicious players.
- Following industry best practices and frameworks for data leak prevention can help prevent unauthorized movement of sensitive information.
- Location screening is a must to locate and block messages from countries of concern. It is also a method to stop spam from unwanted connections.
- Always use SMTP authentication. It prevents unauthorized account access.
The Consequences Of Not Following The Best Practices For Mail Server Protection:
The consequences of not securing the mail server are many and severe, as listed below:
- Unauthorized access to the data of the organization
- Leakage of data
- Spam attacks
- DoS/DDoS attacks
- Total network disruption
How Do Mail Admins Benefit From Following The Best Practices For Mail Server Protection:
Conversely, the benefits that users can derive from adequate mail security are:
- Protection against phishing campaigns
- Prevention of spear-phishing attempts
- Creating a firewall against whaling, email spoofing, and other social engineering techniques
- Prevention of compromising the information systems and denying illegal entry to disrupt operations
The mail server is the gateway to a more fantastic mine of data, and in 2021, nothing is more valuable than information. Malicious actors and cyber-criminals are after data for its immense value.
Therefore, IT security admins and cybersecurity specialists, and mail admins must pay greater attention to the matter and fortify their mail servers.
Hit us up, if you’re looking for a reliable blocklist provider that protects your mail servers at the SMTP level. We do offer a 14-day free trial of our Abusix Mail Intelligence blocklists. If you have any questions, please get in touch and use the contact form below or use the chat at the bottom right.