I keep getting a connection failure error when I try to read an email

Question

I see I have emails - go to click on one and I receive a message that says Connection Failure - sometimes I get a long white screen - the mail screen behind it fades and I can't go back to try again - in the white rectangle that appears is the message broken up - coded - I usually have to back all the way out and try again - sometimes it'll work - or a diff. email will work...?  What is going on.  I did just have my computer worked on - so I"m thinking they changed a setting of some knd.