My mother contacts disappear when she sends a message or call someone, how is this possible and how to fix it?

Question

My mother contacts disappear when she sends a message or call someone, how is this possible and how to fix it?

Answer 1

Technically the limit of 4Gb per folder should have been removed in a recent patch. Personally I an unconvinced as the developers have said so twice before and something else arose to bite people at 4Gb. So the limit probably does not exist anymore and moving mail and compacting will fix it without data loss if it occurs as recent issues have been about displaying mail after the 4Gb point, not storing it.
Use the Ctrl and Shift keys in conjunction with your mouse to make multiple selections.
click followed by Shift+ Click selects everything between the two clicks, including the items clicked.
Holding the Ctrl key while clicking allows you to select or deselect mail to either fine turn the list from shift clicking or to make one of your own.
Ctrl +A selects everything in the list from the current selection to the end.
One option is create an important folder and move your important stuff to it then ctrl +A the whole remaining inbox.