All accounts keep going off line, quitting Mail fixes the issue

All accounts keep going off line, quitting Mail fixes the issue.

I have 3 Gmail, 1 hotmail and a yahoo. Al go off line with a little alert symbol next to them.

If I select take all accounts on line nothing happens.

Email delivery stops.

To fix this, I quit Mail and re launch it. That fixes it.

It's realy annoying.

Any ideas?