You should definitely not send 25 emails a week. I wouldn't advise that. Just so you understand where I am coming from: We have been sending 4 emails per year in the past. To improve the quality and quantity of emails we send I have done this research and shared this knowledge in the post.

When I signed up for loggly they sent me one email every day for a month. I could have unsubscribed but I didn't. Because the emails contained tutorials about the service and I wanted to know more about how their service worked. I can't say I read every email, but I have at least took a glance of the screenshots in the tutorials. So, sometimes if you like the product you want to receive emails. It is a good thing as long as it is extremely easy to unsubscribe.

"It is a good thing as long as it is extremely easy to unsubscribe"

There will never be agreement on this point. Some people will always view incoming email as bad by default, not 'good by default' as you're looking at it. This will never be 'fixed' by 'easy to unsub' processes. It's a philosophical view of the world.