Turn on Archive without archiving mail older than 2 years

[JohannUnivision]

I have an issue where I need to enable a default archive policy of nothing archived.  The goal here is to enable the 50GB of Archive space to allow for the upload of an offline .PST file that a user was keeping.  The .PST file has massive folder structure and is larger than the free space left in the mailbox.  The problem is that I need to make sure that when I turn on archiving I don't archive everything older than 2 years (Which will strip the email from the folder structure that she currently has).  How can I make sure that I can turn it on for this user without automatically archiving anything?   

Under the documentation, there is a warning that is displayed when turning on archiving about the 2 years.  In the explanation the default archive policy is created AFTER you turn archiving on for the mailbox and AFTER the 2 year archive warning is displayed.  How can I ensure that none of the user's mail will be archived (and subsequent folder structure lost).  Is there a delay between turning on the archiving and when the archiving begins?  I've heard it's performed every 7 days, but I can't find anything on how to simply turn on archiving and have NOTHING archived.  I simply want the archive folder available for another 50GB to upload some offline mail into the archive folder.  The user will handle dropping mail into the archive MANUALLY.  

[#2]

@JohannUnivision 

Ok, so after reading through mountains of documentation I've come to two options.  I can modify the DPT (Default Policy Tag) in the Default MRM Policy (Or create a new one and Link it to the Default MRM) to never archive anything and never delete anything (or archive after 30 years or something).

Setup and Archiving and Delete Policy

Or, I can place the mailbox on retention hold, which seems like the right option.

  Place Mailbox on Retention hold

Any thoughts?  I don't think I'll be able to auto archive mail with the user any time soon.  For now and the foreseeable future it needs to be manual.  Perhaps in the future we can figure out a way to keep the folder structure and autoarchive, but the archive is not very useful without that folder structure.  Perhaps I should do BOTH.  Any thoughts?

[#3]

@JohannUnivision 

Here are some of my notes in case anyone else runs into this.  I'll report back how it goes.

MRM  -  Messaging Records Management

Retention Tags must be "Linked" or "Unlinked" to a Retention Policy, the Policy is then applied to the mailbox, and from there, one can select from the retention tags that were previously "linked" to the retention policy.

There are "archive tags" and "deletion tags" What gets archived and when, and what gets deleted and when.

Retention Tags (in general)

A retention tag applies retention settings to individual messages and folders in a user's mailbox. It defines how long a message remains in the mailbox and what action is taken when the message reaches the specified retention age

DPT - Default Policy Tags  [[applies to everything unless an RPT overrides] user can't change]

Applies to entire mailbox and all untagged items.  This is what gets applied by default and is the base policy

RPT - Retention Policy Tags  [applies to specific folders, user has access]

Applies to Folders, it "Tags" untagged items that have the Default Policy Tag (which is really untagged).   These override the Default Policy Tags on a folder level, so that you can specify folders to have a different policy than the Default Policy for the entire mailbox

Personal Tags [Extra specific, user level]

Only for custom folders and individual items, applied through OWA - Outlook Web App

WARNING:  The Default MRM Policy, archives all mail older than 2 years (untagged mail) upon enabling archiving.  There are two ways around this, Change the DPT in the Default MRM Policy and/or place the mailbox on retention hold.

[#4]

If this is a temporary need, just for the import of the PST, you can put the mailbox on a retention hold so that no MRM processing occurs. This will affect things like moving messages to the RecoverableItems subtree as well though, so it's not recommended to keep the hold for a prolonged duration.

Now if the goal is to never ever more items to the archive, simply unassign the retention policy from the mailbox, so that no policy is assigned to it.