Unfortunately 2 of those I almost entirely get spam and business/commercial interactions through. On my cell phone I've gotten one call in the last 6 months that wasn't spam and it was an automated notification from the Sheriff about a permit I'd applied for. I haven't gotten a single useful call from someone not on the whitelist of my contact page in so long it's tempting to just autosend all unrecognized numbers to voicemail.
Email in particular I don't think really fits the mold of social network. I think principally because there's not really a public post concept it's all essentially point to point communications. There are some abstractions like mailing lists but they're still an express list of people who will get it. I guess that might not be so different from a 100% private profile but the lack of any public functionality excludes it from the social media category.