How do I submit a suggestion?

I live in Mission Viejo, CA, and have been a customer for 30 years.  A new e-mail system was recently introduced.  It has a bad design feature.  It assumes that I want to select the next message in my in-box, and automatically checks it.  As an example:  I was highlighting a number of messages in my in-box that I wanted to delete, but the system automatically selected the message following the last one in the group that I wanted to delete, and I deleted that one also.  If I notice the mistake, I can retrieve it, but given the volume of messages I get, I find myself unknowingly deleted messages I want to save.  Can this be fixed?  The old system was better.