Reportabuse. this solution, which worked for me on my iPad 3: " On your iPhone, open Settings app and turn to "Mail, Contacts, Calendars" page. Scroll down to find "Mail Days to Sync" option and set it as "No Limit". Then the Mail app on iPhone will be able to sync all the previous emails, and you will be able to check all 1 On Gmail's desktop website, click the gear icon in the top-right corner and then click See all settings. 2. Select the Filters and Blocked Addresses tab to see all your Gmail filters. The Tocreate a filter in Gmail: Go to your mailbox account. Click the Show Search Options sliders on the right side of the search bar. Specify your filter criteria. From: This filter field allows you to filter emails by who sent them. You can even put multiple addresses here, separated by commas. Typeregedit and press Enter. This will open the Registry editor. In the folder tree on the left, follow the path: HKEY_Current_User > Software > Microsoft > Office > X > Common > MailSettings. If there is a value named DisableSignatures and is set to 1, modify it so that it is set to 0. Back to the list of problems. Method3: Review your Email Filter Settings. The issue of Email not showing up in Gmail can solve by reviewing the filter setting in Email. Let's discuss them. 1. Launch a Gmail account. 2. Hit on the gear icon > See all Settings button > Filters & Blocked Addresses. 3. Havegot two computers, both running windows 10, both with office 365 on. All updated. But on both computers often when you click on a different inbox the emails all appear gone, until you leave, then come back to it and they are back again. Have tried reinstalling office, even reinstalled both computers and it still happens. Ifyou unchecked the option to leave mail on the server they will be deleted from the server when outlook downloads them. That won't affect messages already downloaded to a pop account - however, if you use 2 computers, one with pop, one with imap account configured, then deleting from the server will delete from the imap account too. Thepossible reasons why e-mails suddenly disappear. 1. Messages were manually deleted either due to accidental deletion or were moved or deleted due to your account filter settings. 2. Messages were deleted due to account compromise issues where a hacker might have gained access to your account and deleted the emails. lGOV.