Spammers are certainly not fools. They are aware that their messages are blocked. So they have become innovative in an effort to evade spam filters.
Nowadays they either send the spam messages in pictures with the contents blank (while attaching the spam body as a JPEG in an enclosure), or resort to some very basic ASCII art, as can be seen in the following screen capture.
In contrast to enclosed JPEGs, ASCII messages are much smaller in body size—very often under 1 kb—versus 1MB for static JPEGs or animated GIFs. These messages are not limited to Russian girl dating services, but include pill campaigns as well.
When enlarged from the source view, we see these messages primarily consist of a single letter or number repeated many times to generate visual effects.
Spammers are attempting to sneak past email filters hunting for phrases commonly used in spam. It's a crafty trick because normal spam engines would not filter out just one single letter or number.
If there are any clickable parts in the message, they normally go directly to large free web hosting servers.
These email messages normally originate from East European networks, and are typically delivered to Italy, Germany and North America.
This "art work" may offer users something iteresting to look at, but you should still be wary of visting any sites pushed by these crafty spammers.