(Interrupting the Meetings 101 posts for a short side trip into rules).
Outlook has built-in Junk Mail filters, which do a pretty good job. But sometimes spam may still sneak into your Inbox. If this happens, be sure that you do not load images, click links, or take any steps that might confirm receipt.
By default, Outlook blocks the loading of images and any external content from untrusted sources. This is to your advantage. Spammers often track the loading of images to confirm e-mail addresses. Make sure you keep this feature turned on. (Configure this setting in Tools, Trust Center, Automatic Download.)
You may be tempted to follow the message's unsubscribe instructions - but this is typically a trap. By trying to unsubscribe, you are actually confirming your existence and may get MUCH MORE spam as a result!
No, your best bet is to delete the message. You could simply tap the Delete key. You might even be tempted to right click it, select Junk E-mail and then Add Sender to Blocked Senders List - but this is unlikely to make much of a difference since spammers typically use different addresses to send from each time. (Still, it's a quick step so you should do it!)
Still, Outlook rules are more likely to help you reduce your exposure to spam by letting you filter out messages that contain a word or phrase in the subject line or body that you would never receive from a legitimate sender.
Let's say we wanted to block a message containing the word "Hoodia" (a diet pill that spammers sometimes promote). Right click the spam message and click Create Rule.
For now, ignore the selected conditions section. Select Move the item to folder and pick Deleted Items from your list of folders. Next click Advanced Options and look for the condition with SUBJECT LINE in the subject or body. Spammers are getting smarter and not putting suspicious words in the subject line as much. Remove the default subject line and replace it with whatever word or phrase you want to filter on:
Click Finish to save your rule. If new mails come in with alternate spellings or tactics, make rules for these too. That's all you can really do safely. You may not get your spam level completely to zero, but you can certainly reduce its daily impact on your productivity!