Microsoft says Google has gone beyond reading emails to target users with ads and is now using the information to send ads directly to their accounts, marked as unread emails.
The post explains how the spam from third-party advertisers appears in the Promotions tab within the Gmail web client and are addressed from the 'firstname.lastname@example.org' email account.
'Pushing junk mail to inbox'
"Google violates your privacy by reading every single word of every single email sent to and from Gmail accounts so they can better target you with ads," the post read. "Now, they're going one step further over the line by using that same personal information to spam your inbox with ads that look like real emails.
"Your email provider should protect you from spam, but Google is doing just the opposite; they're reading your private email conversations and using what they find to push junk mail directly to your Gmail inbox."
The ads are only lightly identifiable by a small icon and a slightly different colour shade. As with real emails, these ads can be stared and added to the Primary inbox, Microsoft explains.
"They watch everything you do any use it to make a profit off of you," an accompanying video clip claimed.
The point to all this, of course, is to point how how different Microsoft's own Outlook.com service is. The company is attempting to win over Gmail users by pledging never to scan the content of inboxes for the purposes of targeting users with ads.
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A technology journalist, writer and videographer of many magazines and websites including T3, Gadget Magazine and TechRadar.com. He specializes in applications for smartphones, tablets and handheld devices, with bylines also at The Guardian, WIRED, Trusted Reviews and Wareable. Chris is also the podcast host for The Liverpool Way. As well as tech and football, Chris is a pop-punk fan and enjoys the art of wrasslin'.