Synchronisation problems.
THE USUAL CAUSE
One or more devices configured as POP rather than IMAP.
POP downloads and removes mail.
WHAT TO CHECK
The account type on every device.
WHAT ELSE CAUSES IT
Folder mapping not configured, so Sent and Trash are local only A device not synchronising all folders Subscription to folders not enabled
THE SENT MAIL PROBLEM
The most common complaint.
Sent mail on the phone does not appear on the computer.
Usually the client saving sent mail locally rather than to the server folder.
WHAT TO FIX
Map Sent, Drafts and Trash to the server folders on every device.
WHAT ELSE TO CHECK
That the client is subscribed to all folders That synchronisation is not limited to recent mail
FOR LARGE MAILBOXES
Some clients synchronise only recent mail by default.
Older mail appears missing but is on the server.
WHAT TO VERIFY
Webmail shows the complete picture.
Compare against it.
