How To Send A Secure Email Attachment

April. 30, 2020

1:44AM PST

In a previous blog post, we talked about how most larger email providers aren’t properly protecting your security, which can leave private and sensitive information vulnerable to attack by cybercriminals. If cybersecurity is something that concerns you, particularly when it comes to defending the content of your emails, then you may have decided to take measures that will better protect you by switching to a more secure email provider. If you have; great! It’s a good idea to enhance your online security as best as you can. 

However, while secure email providers may be protecting the information included within the actual message, what about attachments? You see, email attachments are often where the most sensitive information is included. We often email paperwork such as financial documents, mortgage agreements, health records, or other extremely sensitive information as an attachment to an email, and not as part of the email itself. This means that it’s equally important you know how to send a secure email attachment, but most of the resources out there are full of inaccessible tech jargon that can be difficult to understand. So, here’s a simple breakdown of ways to make sure that your email attachments are secure. 

Why Encrypt your File Attachments?

 Here’s the catch; many secure email providers only encrypt your actual email messages and not the attachments that are sent with them. Encryption is, in its simplest and most understandable form, a way to scramble data so that it can’t be read by anyone who you don’t want to read it. It’s important to take steps to encrypt your attachments so that they are unreadable by outsiders and don’t leave you or your clients vulnerable to cybercrime. You need to make sure not only that any attachments you send cannot be intercepted along the way, but that the intended recipient is the only one who can open and read the email. 

How do you encrypt an email attachment?

 There are a few different options when it comes to encrypting email attachments so you can send them securely. There are two main types of encryption that you may have heard of before. Public-Key Encryption, such as PGP (or Pretty Good Privacy), is a popular type of encryption that can be used to scramble sensitive files and render them unreadable, so you can send them securely. Essentially, Public-Key Encryption requires two sets of keys which can be used to decrypt the email on the receiving end. One key is publicly available, while the other is private and shared only between the sender and the receiver. This type of encryption is popular, as it can be done remotely without ever having to meet the person to exchange keys.  The second form of encryption is Symmetric-Key Encryption (such as AES 256), which also involves the use of a key to encrypt the email, but there is only one key used. The sender must share the key with the recipient prior to the email being sent. 

 You can learn how to send and receive secure emails and attachments without the use of a third-party provider, but it can be much more complicated than it needs to be. The best way to encrypt your email attachments is to use a program that does all the heavy lifting for you and makes the process much simpler and more user-friendly. 

 There are programs that can be easily downloaded that utilize either Public or Symmetric Key Encryption to allow you to send a secure email attachment. Some programs work directly with your email provider, while others may involve you scrambling the document you want to send prior to attaching it to the email. With a small amount of research, you can choose a program that suits your needs and use it to ensure the online safety of both you and your clients.


Becker, Ralf, and Hadi Nategh. “PGP vs. S/MIME.” EGroupWare,

Braun, Andrew. “PGP Encryption: How It Works and How You Can Get Started.” Make Tech Easier, 23 Apr. 2018,

“How to Encrypt Email Attachments.” Virtru, 19 Oct. 2019,

“How to Send a Secure Email Attachment.” Trustifi, 20 Dec. 2019,

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