Q: Apple e-mail under the Yosemite OS X is repeatedly making wrong links between the original message and reply.

Hi, I have a long term problem with Apple mail (MacBook Air) and it does not seem to go away with system upgrades. The same happens on my Mac mini. Sometimes when I reply to a message the original reply is sent (you hear the sound), but i gets lost in the history (cannot be found) and a wrong link between the original message and the reply (link via "the arrow" sign) is being made (i.e. it links a completely different message and the reply cannot be found). Anyone having the same experience? Also, when I move between different desktops the Mail app often fails. Furthermore, sometimes when I leave the computer for a while (say 10-15 minutes), the Mail app will often hang. Anyone having the same experience? Thanks, Zed