Google Gmail Users Hit By Deleted and Lost Email
06/27 Update: according to several posters, Google has confirmed this is a Microsoft problem rather than Gmail which means users will have to wait for a Windows 10 update rather than a Googles server-side tweak. In addition to the workarounds detailed below, an additional temporary fix has been found:
-Gmail.com > Settings > Filters and blocked addresses > Create a new filter
-In ‘From’ field enter your address
-Click ‘Create filter’
-On the next page, select ‘Never send it to Spam’
-Click ‘Create filter’
This workaround isn’t perfect because it creates two sent items in Windows Mail but it does stop Gmail emails being lost or deleted which is the most important thing until Microsoft comes up with a fix.
Source: http://wepicker.com/blog/google-gmail-users-hit-by-deleted-and-lost-email/