A folder is either specified by ID or by one of the following well-known folder names: .Get messages | Synchronize messages | Create and send messages | Reply or reply all to messages | Forward new or drafted messages | Update messages | Delete messages | Move or copy messages |Manage Focused Inbox | Manage @-Mentions (preview) | Manage rules (preview) | Unsubscribe (preview) | Get language choices (preview) | Get time zone choices (preview) | Get mailbox settings | Get auto reply settings | Update auto reply settings | Get Mail Tips (preview) | Get attachments | Create attachments | Delete attachments Folder operations Mailbox folders can contain messages and other folders.As a result, you'll need the account up manually if you want to use encryption.
The problem seems to affect all folders but only emails after about 6-12 months old. Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).
This message doesn't mean that the mail server doesn't support encryption, it just means Outlook's Auto Account Setup can't determine the correct settings to use.
This is caused by incomplete or missing autodiscover records in DNS.
It gives you easy access to Outlook settings and data folders and allows you to change settings that are normally only possible through the registry. After applying the June 2017 update for Outlook 2007, 2010, 2013 or 2016, attachments that are safe (txt, docx, xlsx, pptx, pdf, etc…) may be blocked as well and can’t be unblocked by Outlook Tools either as this is due to a bug in Outlook itself.
For more information, workarounds and solutions see; Attachments are blocked after applying June 2017 update – Fixes available now.