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How to Secure Your Email Server

By December 20, 2021December 22nd, 2021No Comments10 min read
Secure Your Email Server

Your company will collect a lot of important data. Thus, your staff needs to deal with this sensitive data. A data leak can be extremely harmful to your business. It can destroy your entire business. The information of your customers might get leaked in a data leak. Due to this, your customers will lose their trust. They will start working with other service providers. Thus, it is important to ensure that you are protecting your customer data.

There are various security solutions that you can use for improving your security. However, one of the most important things that you need to protect is your company email server. There are various methods that you can use for protecting your email server. Email data leaks are becoming more serious with time. Thus, you should immediately start working on protecting your email server.

Why email security is important?

  1. Avoid Business risks

Your employees might be sharing important data via email. Thus, you can’t send unencrypted emails to your employees. You can use encryption for solving this problem. This will ensure that attackers can’t read the content of the email. If you want to avoid business risks, then you should focus on protecting your email server.

  1. Protect Confidential Information

Email security will help you in protecting confidential data like credit card numbers, passwords, and social security numbers. Attackers will generally try to trick your employees into sharing confidential data with them. This is mostly done by using social engineering or phishing attack. If you are protecting your email server, then you can reduce the possibility of a phishing attack. It will ensure that very few spam emails will reach your inbox. You should still ensure that your employees know about the best IT security practices. However, you should also focus on reducing the possibility of a phishing attack

  1. Avoid Identity Theft

If an attacker gets access to your employee username and password, then they will get access to your entire email server. They can read the emails that your employees are sending to another employee. This is known as identity theft. Attackers can also use your employee email for tricking other users. They can send emails to your third-party vendors. Attackers can get access to other important data by stealing one employee’s password.

  1. Unprotected Backups

Most attackers are using SMTP as their outgoing mail servers. The backup of these servers will store everything in text format. These backups will be present for decades. If someone gets access to these backup files, then they can read all the emails. This can be very serious for your business as your competitor might get access to this data. You should focus on protecting the email backup.

  1. Repudiate Sent messages

It is very easy to forge a legit email message. You need to do a lot of stuff for differentiating between a legit and fake email message. If you are using the best email security tactics, then you can block spam messages from your mail server. It will help you in using advanced techniques for blocking fake email messages.

How to Protect your Email Server?

  1. Encrypt POP3 and IMAP Connections with TLS

IMAP or Internet Message access protocol is widely used. It is the standard Internet protocol that companies are using to retrieve messages in their inbox. If you have a TCP connection or IC, then you need to use IMAP for retrieving messages. POP3 or Post Office Protocol is also used in the industry. It works at the application layer.

The main problem with POP3 and IMAP is that both protocols are not secure. They are not using authentication protocols. MS Excel is using POP3 and IMAP protocol. Thus, you should ensure that you are not sending and receiving unencrypted messages. You should use SSTLS for authenticating your message. This will increase the reliability of your ingoing and outgoing emails. You can do your business without worrying about unencrypted emails. SSTLS will help you in securing your email protocols.

  1. Add DKIM

DKIM or DomainKeys identified mail will also help you in protecting your email server from data leaks. It will help you in ensuring that your business inbox is free of phishing and spam. DKIM will at least help you in reducing the instances of these kinds of attacks. It is very important for your business as most data leaks occur due to phishing attacks.

If you want to protect your employees from phishing attacks, then you should start by using DKIM. It will help you in blocking most phishing emails. DKIM will help you in verifying that the domain present in the email is legit. The authentication protocol will give a digital signature that is connected to a domain name. This will ensure that you can verify the domain link. After that, all you need to do is research a DNS or Domain Name System public key for a valid digital signature.

This will help you in protecting your employees from phishing and social engineering attacks. Most attackers will generally use these attacks for targeting your employees. You can use DKIM for filtering out these spam emails from your employee’s mail.

  1. Use SURBL

The SURBL or Spam URL Real-Time Block Lists is very important for your business. This security solution will help you in reviewing the links that are inside an email. It will look for links that are invalid or malicious. SURBL will block all these emails before they hit your inbox.

If your employees are busy, then they are probably not going to check the links that are present in the mail. They might directly open the hyperlink without checking it. Due to this, your company will be open to malware and phishing attacks. If your company is phished, then you can lose important data like credit card details and account numbers. Your employee’s credentials can get stolen. Attackers can use their username and password for logging into your network. Thus, they will get access to your entire network.

Malware attacks can destroy your computer or network. The most dangerous malware attack is a ransomware attack. Most business owners already know about this attack. In this attack, your system and network will be locked. You need to pay ransom to attackers for decrypting your data. This can be a very bad situation for your business. Thus, you should ensure that you are always using SURBL for protecting your network.

  1. Turn on SPF

SPF or Sender Policy Framework can also help you in protecting your email server. It will help you in authentication emails. This will tell when a sender is spoofing or forging an email address. It is good for your business as your employees can’t manually check this. Spoofers are becoming smarter with time. It is very difficult to differentiate between a legit and forged email address. Thus, you should leave this task to SPF.

If you want the best result, then you should ensure that you are using SPF with DMARC. DMARC is known as Domain-based message authentication, reporting, and conformance. It is offering various protective measures against spammers and email spoofers. You can limit phishing, email scams, and cyber threats by using DMARC with SPF. These attacks can wreck the integrity of your entire business.

  1. Change Email Relay Settings

Most email servers are using open mail relay set as it is the default setup for SMTP servers. If you are using open mail relay, then your server will allow everyone with the internet to message your server. Both known and unknown servers can send messages to your email servers. Attackers and spammers can easily exploit this. They generally use open relay settings for sending spam emails to your employees.

All you need to do is turn off the open relay settings. If you can’t turn off the relay settings, then you should set up IP parameters. This will ensure that not every email will hit your email server. Your IT team can help you in changing this setting. It is a small change but it will help you in stopping most attacks.

  1. Keep Server Connections Limited

If you are using a Simple Mail Transfer Protocol or SMTP server, then you should ensure that only limited connections are open at one time. Attackers will generally try to bring down SMTP servers by using DoS or denial-of-service attacks. DDoS is a cyber-attack where your computer service or network is disrupted. The effect of this attack can be permanent or temporary.

Your server is always vulnerable to a DDoS attack. An attacker can send a huge amount of data to your network. Due to this, your network will crash and you can’t do anything. If a lot of users are using your server, then it is difficult to detect a DDoS attack.

You should still consider limiting your server connections. This will help you a lot in making your server robust.

  1. DNSBL

You should also use Domain Name System-Based Blackhole list or DNSBL for protecting your network. This service is also known as RBL or Real-Time Blackhole list. It will use DNS for determining if the IP addressing sending mail to your business is blacklisted for spamming. It will help you in blocking spam emails.

The best thing about DNSBL is that you can review multiple lists at the same time. You can use worldwide DNSBL servers for providing even better protection to your users. This will ensure that spam emails won’t interrupt your daily operations. Your employees don’t need to worry about spam mails in their inboxes. This will help you in maintaining your customer satisfaction.

  1. Reverse DNS Check

A Reverse DNS lookup can also help you in protecting your business from data leaks. It can help you if the domain names and the IP address are associated via PTR records. PTR is simply a pointer DNS record. Reverse DNS lookup will help you in combing through registries and registrar tables.

You can use Reverse DNS lookup for finding the spammers that are sending spam messages. If someone is trying to attack your network by turning off your firewall, then rDNS will alert your IT team. They will tell the domain name of the computer that is attacking your network. You can also find the ISP of the attacker’s computer.

The information provided by the reverse DNS lookup won’t be very specific. For example, you can’t find the first name of attackers by using this technique. However, you will have trackable data on a spammer and attacker. This can help you in protecting your email server from known spammers. You will be one step closer to finding out the real attacker.


It is very important to protect the proprietary data of your business. One data leak is enough to destroy your entire business. Thus, it is important to ensure that you are protecting your email server from attackers and spammers. The methods mentioned in this post will help you in safeguarding your email server. However, you should ensure that you are still using common sense. You should still check links for spam. Also, your employees should never open an attachment from unknown emails. The best way to protect your employees is by using an antivirus. It will help you in removing the virus from your employee’s system. You can also use an attachment checker for checking all the attachments.

A well-protected email server will help you in maintaining your customer trust. It will ensure that you are protecting your confidential data. However, email security is only one part of this big puzzle. You also need to protect other things in your network. The best way to do this is by working with a good MSSP. Experienced MSSPs like Bleuwire are helping SMBs in improving their security. They will help you in creating a unique IT security strategy for your business. You don’t need to worry about integrating IT security solutions with your architecture. Bleuwire will also help you in securing your email server. Thus, you don’t need to worry about implementing the methods that are mentioned in this article. If you need more information regarding IT security services, then you can contact Bleuwire.

Contact us today to learn about Bleuwire™  services and solutions in how we can help your business.