We all saw this coming. On Thursday, Google introduced deeper Google+ integration into its email service to allow any Google+ user to send each other Gmail.

It’s the search giant’s latest push to make Google+ the glue that holds together all Google services. This writing has been on the wall for a while now. Last year, Google began requiring Google+ accounts for all YouTube users who wanted to comment on videos. And Gmail inboxes are starting to fill up with constant reminders alerting users to “what you missed” on Google+.

But as Google continues its effort to tie all its services together in a neatly wrapped package, users are slowly feeling the pressure to conform to Google’s standards. Many don’t like it. (Just check out the comments to this ReadWrite piece about the YouTube change.)

That’s not to say Google is changing everything in one fell swoop. In fact, with each new service it announces, Google anticipates backlash and makes updates less intrusive than they might be perceived. For instance, while the Google+ and Gmail contact integration is a default, the company gives you a variety of options to let you control who on Google+ can email you. That includes no one (although you have to take the initiative to change that setting yourself).

As Google+ begins to become the platform all of Google is built on, our control lessens. At first, anyone could comment on YouTube. And then YouTube was linked to your Google+ account (if you had one). And then an account was required to comment on a video. And then everyone freaked out.

The Biggest Problem With Google+

People who use Google+ for professional connections could benefit from the new Gmail feature, but it compounds the intrinsic problem with Google+—many users have multiple accounts. I use my personal email as my main Google+ account, but my company email is also associated with a separate Google+ profile.

Google+ isn’t just Google’s version of a social network. It’s the entire social layer Google is built on. That includes our communications (emails), personal relationships (Google+), and media consumption (YouTube).

But in order to consolidate the social layer, Google needs to find a way to streamline the online identity. We usually just have one Facebook, Twitter and LinkedIn profile for friends, followers and colleagues to connect with us. It’s easy to keep those contacts in their separate buckets because each service provides us with one, unique identity.

And with all those services, people can connect with us directly.

Facebook warmed up users to the idea that anyone on the social network can send you a message. The company rolled out @facebook.com email addresses in 2012 that let anyone with a traditional email system—like Gmail—send you an email that will end up in your Facebook messages.

Twitter tried something similar last year when it gave users the option to receive direct messages from any Twitter user. After a month, though, Twitter quietly removed the feature, offering no reason beyond a link to the blog post that explained Twitter’s experimentation policy. People were worried that opening up direct messages would increase spam, though I opened up my Twitter DMs that month and only received messages from credible Twitter users.

With Hangouts, the text and video messaging service linked to Google+, users could already message each other, though the receiver had to confirm the chat request before seeing any messages appear as a chat window. Now, though, messages will wind up in your Gmail inbox.

Email—Where Messages Go To Die

When Google released new inbox categories last May, it essentially added an additional spam filter for your messages. Sales and coupon offers and annoying email newsletters suddenly got shunted to the “Promotions” tab, leaving your main inbox free for only important messages.

With Gmail’s Google+ integration, messages from people you’re not connected with on Google+ will go into the “Social” category, meaning they’re deemed less important that your other emails. What does this remind you of? Oh right, spam.

Some people don’t have the Gmail categories activated to parse emails. But everyone is used to getting spam, from newsletters we signed up for years ago to notifications from long-forgotten applications we don’t remember downloading. So these Google+ messages will fit right in to the deluge of communications we’re already receiving.

For now, Google is giving us the option to opt-out of the Google+ email feature. But as we saw with YouTube, options can quickly turn into mandates. And Google is making it harder and harder to avoid them.

Lead image via Flickr user meneame comunicacions, CC 2.0; Google Minus image by Madeleine Weiss for ReadWrite