Exchange Online, Retention policy flow?

Solution 1:

A mailbox can apply one retention policy, one retention policy includes one or more retention tags: Apply a retention policy to mailboxes

Therefore, what kind of retention action depends on the retention tags, for retention tags, there are three types, they are:

• Default policy tag (DPT): Automatically to entire mailbox. A DPT applies to untagged items, which are mailbox items that don't have a retention tag applied directly or by inheritance from the folder.
• Retention policy tag (RPT): Automatically to a default folder. Default folders are folders created automatically in all mailboxes, for example: Inbox, Deleted Items, and Sent Items.
• Personal tag: Manually to items and folders. Users can automate tagging by using Inbox rules to either move a message to a folder that has a particular tag or to apply a personal tag to the message.

For personal tag, users can apply a retention policy to user-created folders or subfolders and individual items (including subfolders and items in a default folder), but not to default folders(e.g. Inbox, Sent Items, Deleted Items). And you could select the personal tag in Outlook/OWA:

In your case, there are three kinds of retention tags:

DPT: 1 Month Move to Archive(Default), if you apply this retention policy Support Inbox Policy to mailboxes, it will work for items in folders which haven't been assigned other RPTs and PTs, after 30 days, it will move these items to archive .

RPT: 6 Month Delete(temporary recovery) and 6 month delete from Archive. The former will soft delete items in the Inbox folder 180 days later, the latter will delete(Maybe it is to permanently delete) the items in Archive after 180 days.

PT: 6 Month Delete. It will delete items in user-created folders or subfolders and individual items (including subfolders and items in a default folder) after 180 days, and you need manually choose it in Outlook/OWA.

The relationships between the three retention tags are like the following: