Unfortunately it's pretty normal, or rather common.
Theres very much an unspoken culture these days of being expected to respond to messages on email/Skype etc out of work hours - as much for management as the layers under them, especially for those looking to progress in companies and organisations.
I used to be terrible for this all through my late 20s and 30s - there was always a feeling I HAD to do it and it definitely put a strain on our relationship from time to time. Weekend breaks, checking while the kids are getting ready for bed etc - it creeps up on you and the pressure can be really damaging to domestic life.
Now that I'm a bit older, I've forced myself to stop - just drawn a line in the sand and said I'm not doing it. If I'm on holiday and theres a work 'crisis' people cope and dont think any less of me.
After 6pm, as far as I'm concerned, work is over. It's done wonders for my general mental health. And the thing is, it's made NO difference to my performance professionally. If anything it's made me more productive.
Basically, incessant emailing/checking is a personal choice - through professional guilt mostly - and when you stop doing it the world doesnt fall apart and everyone is much happier.
At least in my experience! :)