I have a quite new Samsung Galaxy Tab S2 which is fully updated. My wife uses the same email address and ISP as I do on her fully updated iPad 2. Both our settings are IMAP and work well. Both machines are set to sync mail. Some syncs fine but much does not. I cannot always see what she sends in the outbox and she cannot see what I send from my S2. No aircraft mode, syncing on, both IMAP, rebooted both. I have checked the Web for solutions but no good. Suggestions would be appreciated.