OK

Limited network congestion on site for a short time (1 hour at most)

Users will need internet access to browse their emails beyond 1 month

Limited network congestion on site for several hours (up to 3 hours for many sites)

Users will need internet access to browse their emails beyond 3 months

Limited network congestion on site for a full day for many sites.

Once downloaded, 1 year mails accessible from outlook without internet access.

 Medium: fewer “network is slow” incidents, but more end-user questions like “I can’t find older emails in Outlook” / “Search doesn’t show old mail” (they’ll need to use Outlook Online to access >1 month).

 Some tickets for how to access archives/older mail and user guidance.

Low–Medium: good balance; fewer “older mail missing” tickets than Option 1.

 Some performance/sync complaints may remain in the first hours, but generally manageable.

Medium–High: more Day‑1 slowness risk (longer caching), leading to more tickets (“Outlook stuck/slow”, “can’t send/receive”, Teams call quality issues due to congestion).

Fewer “older email missing” questions, but more performance/network-related incidents.

More change-management effort due to behavioral change for users.

 Low–Medium: same type of controls as Option 1, but less user disruption and fewer exceptions.

Standard monitoring and comms.

Medium–High: higher need for Day‑1 command center, active network monitoring, potential reactive throttling, and site-by-site troubleshooting.

More coordination with network team.

Low direct cost (configuration/policy + comms).

Low direct cost.

Low direct cost for configuration.