how to fix outlook 2016 not syncing mail folders with telstra webmail

If the missing emails are still visible in Outlook, do not remove the old account or delete any Outlook data yet. The emails may only exist in your local Outlook data.

Changing from POP3 to IMAP does not automatically upload your old POP3 folders to Telstra Webmail. IMAP only syncs the folders that are stored on the mail server.

I would first make a backup of the existing Outlook data. After that, you can copy the missing emails from the old local folders into the matching folders under the new IMAP account. Outlook should then upload those messages to Telstra, and they should become visible in Webmail.

If the emails are missing from both Outlook and Telstra Webmail, do not continue with any account reset until you locate the old PST file, because that may contain the only remaining copy of the messages.

Hi Rod Prior,

Thank you for clarifying. If the missing messages are still available in Outlook but not in Telstra Webmail, please do not clear the offline items, rebuild the cache, remove the old POP account, or delete any Outlook data files yet. Those messages may be stored only on the computer, and resetting the local data could remove the only accessible copy.

First, back up the affected folders by exporting them to an Outlook Data File (.pst) through File > Open & Export > Import/Export > Export to a file > Outlook Data File (.pst). Make sure Include subfolders is selected, then confirm that the exported file can be opened before making further changes.

After the backup is secured, right-click the Telstra IMAP account in the folder pane, select IMAP Folders > Query, and subscribe to any missing server folders. You can also select Update Folder List. If the old POP messages still do not appear in Telstra Webmail, they will need to be copied from the old local Outlook folders into the corresponding IMAP folders, preferably in small batches, and then checked in Webmail.

Please also clarify whether the missing items are currently visible in Outlook but absent from Telstra Webmail, or visible in Webmail but absent from Outlook, as the correct next step depends on where the remaining copy is stored. Thank you so much for your understanding.   

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