Repeat after me : Spark is my friend.

[ogs]

Just as raph972 says: they are almost certainly hitting Amazon and Microsoft for the AWS and Azure services respectively, which act as a kind of CDN (content delivery network).

This is basically like a huge hard drive on the internet where you can store stuff (in the cloud), and then deliver it quicker to the end user because you can choose to locate that hard drive physically closer to the user.

There's nothing sinister about those IP addresses. I don't know what Spark is making those connections for, but those are not shocking or unexpected endpoints.

I would not use shocking, but the OP reports that his firewall blocks these connection attempts. Spark seems to function properly even if this is blocked. In that case the connection attempts should not be there. When @mac enables one or more of the services that require a connection to AWS or Azure it would not work as long as his firewall is blocking these connections. He'd then have to open up his firewall for the specific traffic to make it work.
Most people only have a simple NAT between internet and their home network. Then "everything" will work, including malware and bot-nets. A next gen firewall to protect your home network is a good thing in my view.