This alert is a reminder to be particular vigilant when opening email from unknown sources. Some of this you already know. However, given the dramatic increase in malicious activity in recent years, it is prudent to have this reminder.
Some emails are particularly malicious in that they are classified as a "wiper" message. These messages are a type of Phishing email. If the code associated with these emails gets executed, it could wipe a hard drive clean.
Please use extra caution. If you receive an email that purports it being from MS Exchange, Outlook Online, or a Voicemail message please use extra caution when opening and do not click on any attachments. In addition, if you receive an email from someone within the company where the reply-to email address does not match the From Name, please forward the message to the support desk. (e.g. David Pritchard [dpritchard@esxi.net]) Finally, if you receive a message from someone in the company asking you to purchase gift cards, wire money, change direct deposit, obtain a money order etc... please verify with the person allegedly sending the message verbally before clicking on any link in the email or performing any actions. (These Phishing messages typically have the persons name correct. However, on closer examination the email address is not accurate. (e.g. David Pritchard [dpritchard@esxi.net]))