EMAIL FORMAT CHANGING

For some CRAZYYY reason which I can not figure out, anytime someone sends me an email & the subject heading ends in a period & then I drag & drop the email to a folder so I can keep as a record, IT WILL NOT OPEN. I used to have windows 7 & now I have 10 and still does it. By the way, I use Live Mail & I assume this is the problem. My co-worker has always used Outlook & he does not have this problem. For example: Subject heading may have the name of a company with incorporated be abbreviated. "Inc." If they would just put Inc & leave period off, everything is fine. I can forward any email to my self & delete the period & get around it, but it's just the fact it drives me crazy! We deal a lot with the same companies & I usually explain the problem & ask them to resend & delete the period themselves. I figure after asking them enough times & driving them crazy about it, they would remember not to add it. IS THERE A WAY TO FIX THIS PERMANTELY OR IS IT JUST A BUG WITHIN THE PROGRAM?