questions

I have some science and technology questions

     Let's deal with science first.  (And for those of you concerned my fine Chicago Public Schools education did not stress sciences, I assure you I took science classes.  We had an open house when I was in a biology class.  The teacher had a movie she wanted to show.  The shades in the room were not working.  She wondered how parents would be able to see the movie during the open house because the sun would be shining in the west windows.  I pointed out the sun would be set by the time the open house was, so that was not a concern.)
     I bought some ice melter for the sidewalks. Pet friendly, says the label.  I have it out in the garage except for a one pound can I have inside the front door so I don't have to tramp through the house to get salt.
     Today I noticed the stuff had congealed in the container inside the house.  It is now one block.
     Why?  Humidity in the house?  Heat in the house?  A combination?
     Technology question.  I checked my e mail about 5 tonight.  One message.  I checked again just after 9 and I had 14 messages, some from this morning that I did not see until tonight.
     Where is the e mail hiding?  Is it floating around in cyber space looking for a landing?
     That's it.  My questions.  All reasonable answers will be read.
Peace and Love