Q: My Outlook e-mail program keeps receiving similar spam messages, even though I've labeled them as junk and blocked their senders. These e-mails have little rectangles between the letters in the subject line, and come from strange-sounding e-mail addresses (I've attached examples.) What can I do to stop this?

Gary Eickmeier, Lakeland, Fla.

A: You receive these e-mails because Outlook's spam filter doesn't recognize them as junk. You can improve the filter's performance with a setting change but you cannot stop spam.

These messages aren't recognized as junk because of the way they are written. If the e-mail's subject line was correctly spelled — such as "Heart Attack Defender" — the filter probably would have classified it as spam.

But with its present settings, the filter didn't catch the e-mail because the subject line is interspersed with nonalphabetic symbols: "He*art Att*ack Defend*er" (I have used the "*" symbol to represent the rectangular shapes in the spam you received.)

This is just the latest efforts by spammers to evade filters. Other classic spam subject lines include creative spellings such as "F*R*E*E." See "Common Spammer Tricks" at tinyurl.com/y3bbxz9d.

Your initial response was to block the e-mail sender, but that's not effective because the "from" addresses in spam are typically faked. Because each successive spam message is given a new fake address, it bypasses your list of "blocked" addresses.

To overcome this trickery, make your spam filter more "aggressive." Here's how:

• Change the setting on Outlook's Junk E-mail Filter (see tinyurl.com/ycb9jrk9). The setting choices are no filtering, low, high or "safe lists only" (the latter means you will receive only e-mails from people you specify.) Note that there's a risk in increasing the filter's aggressiveness. While you should see less spam in your inbox, some legitimate messages may be inadvertently classified as spam. You will need to periodically look in Outlook's "Junk E-mail folder" to make sure you're not missing e-mails that you want to receive.

• Try one of several non-Microsoft spam filter programs that are compatible with Outlook. (For a list of filter programs — some free, some for-pay — see tinyurl.com/y4evz65j).

Q: When I post a photo to Facebook from my iPhone 6, several additional photos are posted without my permission. I use Facebook's Photo/Video command that supposedly allows me to choose which photo to post. How can I post just a single photo?

Alan Fossum, Minneapolis

A: Use the iPhone's posting software instead of Facebook's Photo/Video command.

Don't open Facebook. Instead, open photos on the iPhone, call up the photo you want and click the icon at the lower left of the screen (it looks like a box with an up-arrow through it.) In the next screen, your photos are at the top, and the picture you have selected should have a checkmark at the lower right. Above the photo it should say "1 photo selected."

Below the photos are icons for the apps to which you can send the photo. Click the Facebook icon and you will see a menu that displays your photo and asks you to say something about it. When finished with that, click "post."

E-mail tech questions to steve.j.alexander@gmail.com. Include name, city and telephone number.