Normally the spam filter is brilliant on Google’s Gmail service. But there is one type of spam that gets through its filter. Probing spam. The content of this type of spam is just some random English text with no links or even a call to action. It doesn’t really make sense. Each sentence is scrapped from different Wikipedia articles. Here’s an example of this type of spam:

hi there

He showed some samples of adapted texts to both Muravyov and Kornilov in February 1864. Army Arts and Crafts Program, then headed by Eugenia Nowlin.
Hong also realizes that he truly cares for his son, who is all that he has left in the world. Irish word for tree.
Egypt was involved in several wars during his reign. US Lacrosse have a chapter hall of fame.
Commonwealth of Kentucky in 1946. Its density is 191. Imperial Society for Teachers of Dancing.

On its own you might wonder what is the point of this type of spam. What you need to do is look at a bunch of probing spam messages and look for patterns. What I found was that only one or two messages were going to each user on a particular domain. The spammer was probing the domain to see which usernames (the part in front of the @ symbol) wouldn’t give a delivery error. They can then use that validated list to send the usual spam messages.

The good news is Gmail can catch these proper spam messages, so I never see them. But these probing spam messages are still annoying and problematic. I do mark them as spam, in the hope that Google’s clever spam machine learning algorithms will eventually catch on to this type of spam.

Update

I just took a look at my Gmail spam folder and I did find a couple of these probing messages in there now. Google learns quickly.