Mac OS Mail App Preview Malware

You can view SPAM emails without any threat, but do not click anything within them. You can cut down on the SPAM and Phishing nonsense by taking advantage of Apple Mail's Rule settings, or you can install SpamSieve.

I used to get dozens of undesirable emails per day, and wrote some Apple Mail rules, and forwarded the crap emails to Apple at reportphishing@apple.com. You would right-click on the crap email and select Forward as Attachment, which opens a new Mail compose window. Set To: to that apple address, and add no text to the outgoing mail body. As a result of these two actions, my phishing/SPAM emails have dropped to 1 -3 per day at most.

Unrelated to Apple Mail, if you want to interactively check for malware on your Mac, then install Malwarebytes. Its trial is fully featured and it will run in the background to catch malware. After the trial, you run it interactively (free) as the "realtime" feature requires the optional subscription. Many of us use and recommend Malwarebytes without any compensation from the vendor.

Bitdefender is an anti-virus application and there are no viruses on Macs. Generally, we recommend that you remove all anti-virus software as it has a long history (reported in these communities) of false detections, valid operating system files removed, and interference with the normal security processes built into the operating system. The only tool we recommend is Malwarebytes because that is all it looks for, and does not get entangled with the operating system.