Why you should not drag and drop mail into Zimbra

Why dragging mail from Outlook into Zimbra loses messages, and what to do instead.

A common approach is to drag messages, contacts or calendar entries from an old profile or a PST file into Zimbra through Outlook, or to use Outlook's own import tool. Neither is safe.

What goes wrong

Corrupt or incomplete items are skipped without telling you. Worse, they often still appear in Outlook afterwards, because Outlook is showing you its local copy rather than what reached the server.

The gap usually goes unnoticed for weeks. By the time anyone spots it, new mail has arrived in the Zimbra mailbox and a clean migration is no longer possible, while other devices sync from the server and show an incomplete set.

What to do instead

Let Zimbra collect the old mailbox directly, then move the messages into your folders. See moving mail into Zimbra from another mailbox.