Can just receiving or opening a spam email put my computer or emails data at risk?

Question

Sometimes you receive some emails which are mostly (and correctly) categorized as spam email by your email provider and you are almost sure that they are in fact spams. However, you are curious to open and take a look at the contents of some of them to see what they have. I was wondering is there any risk involved at receiving/opening such emails, of course without clicking on any of its links or downloading its attachments? Is it recommended to not even open them at any case?

Further, It would be great if you could consider and compare in your answer the cases of using an established email provider (e.g. Gmail, Yahoo, Live, etc.) vs. the ordinary (self-hosted) email systems, as well as the difference (if any) in this regard between using internet browsers for viewing email vs. using email software clients (e.g. Mozilla Thunderbird, Microsoft Mail, etc.) or mobile email apps.

Answer 1

The majority of the emails programs organize the messages on two formats:

• All the messages in one file.
• One file per message.

Is fine if you open the file message with vim, notepad or so program that don't do any parsing and potentially can execute something such as attachment, or follow a HTTP link. With any other program I will be skeptical of opening but just because I don't know what is going to do the program that opens the message with an infected body part for example.

Answer 2

No high risk threat (no data compromise if you don't click on anything) as long as JavaScript is disabled in an email service, Most of them do disable that. By doing some tricks, Like Embedding an Php page as hidden in the body of email, Which leads to be malicious and be flagged as spam, The attacker can get log of your location, ip, Browser version, Monitor resolution, the amount of time you spend on reading that, the heatmap of your mouse and etc which can be used in further social engineering attacks.

I personally have tested Gmail, Yahoo, Live and their security filters is very acceptable and is hard to bypass.

Generally most malicious (spam) emails are:

1. Using an hidden php page to log and track their attack
2. Using Malware as attachment
3. Using common content like jobs, password recovery, Asking for Ransom and ...