GMail spam filtering algorithms are pretty good at detecting text spam messages. The moment you receive an email about a Pharmacy store selling Viagra, Levitra, Cialis, Valium and other pills, GMail will mark it as spam.
Then entered image spam where the text message is sent as a picture attachment to bypass the spam filters.
There are effective methods to beat image spam but the latest spammer trick involves sending email messages with misspellings of words as you see in the screenshot above.
The word Viagra has been spelled as \/laGr@ - the first alphabet is not "V" but a combination of a back slash and a forward slash. The second alphabet is "L" instead of "i". No wonder, Gmail failed to detect this message as spam and delivered it to the Inbox.
And there's more - the image attachment, that has the actual advertising message, is scribbled with short horizontal lines so as to trick the OCR software that can extract text from images.