Outlook Classic vs. New

Summary

New Outlook has begun to appear on campus, even though it's not fully-baked.  This article will define the reasons you may or may not want to use "New" or "Classic".

Feature

Classic Outlook (Windows)

New Outlook (Windows)

Outlook on the Web

Guidance / Notes

Snooze Messages ❌ ✅ ✅ Temporarily hide an email from your inbox and have it reappear at a later time you choose, similar to Gmail's Snooze feature.
Add Email Reminders (Including Custom) ❌ ✅ ✅ Can be added to events created in Classic using New or Web.
Duplicate Events ❌ ✅ ✅ Events created in Classic can be duplicated using New or Web. The duplicated meeting will keep the original meeting's chat history.
.ics Files ⚠️ cumbersome ✅ right-click a calendar event and select “Save as .ics ✅ right-click a calendar event and select “Save as .ics  

Offline use

✅

⚠️ (partial; improving)

❌

If you travel/work with spotty internet, Classic is safest.

PST files (.pst)

✅

⚠️ (significantly improved)

❌

If you rely on PST archives, Classic is more complete.

Mail merge

✅

⚠️ 

New Outlook now has its own mail-merge experience

⚠️

Microsoft has been rolling out native mail merge capabilities in New Outlook and OWA, but traditional Word-to-Outlook MAPI mail merge is still not equivalent to Classic Outlook.

Quick Parts

✅

🕒 (coming soon)

—

Use Classic until New catches up.

COM add-ins / VBA

✅

❌

❌

If you depend on legacy add-ins, stay on Classic.

Web add-ins (Office Add-ins)

✅

✅

✅

Modern add-ins are supported across experiences.

Multiple profiles

✅

🕒

❌

If you switch between separate Outlook profiles, use Classic.

Shared mailbox (folders)

✅

✅

✅

Works across endpoints.

Shared mailbox as account (manage rules/categories/OOO)

✅

✅ (Some delegate scenarios remain partially available)

—

 

Rules (complex)

✅

⚠️ (partial)

⚠️

Classic tends to offer more for complex rules.

Folder colors

❌

✅ (does not sync to Web)

✅ (does not sync to New)

New/OWA advantage; note one‑way/unsynced behaviors.

Pin messages

❌

✅

✅

New/OWA support pinning.

.EML / .MSG / .OFT handling

✅

✅ for .eml; ⚠️ for .msg/.oft

❌

If you regularly handle .msg files, Classic is more reliable.

Notes module

✅

⚠️ (partial)

❌

If you use Outlook Notes, Classic is safer.

Distribution lists / groups (UX)

✅

🔁 Revised experience

🔁

Experience differs in New; often managed via portal on Web.

Contact lists (basic)

✅

✅

✅

Basic contact lists work across endpoints.

Share a Contacts folder

🕒/⚠️ (investigating)

🕒/⚠️ (investigating)

🕒/⚠️ (investigating)

Microsoft lists as "Investigating".

Copilot features in Outlook

✅

✅

✅

Available where licensed.

Drag attachments ✅ ⚠️ (drag to Windows Explorer or download)    

Drag calendar item to other calendar

✅

❌

❌

Classic only per internal notes.

Drag message to desktop / Save message file

✅

⚠️ File > Save As (EML)

—

Different file handling between Classic and New.

"File" menu in Calendar

✅

❌

✅

Classic and Web have a Calendar File menu; New does not.

Forward from Group mailbox

✅

❌(item type invalid)

—

Forwarding from Group mailbox not available in New (per notes).

Roaming Signatures

❌

✅

—

Roaming signatures supported in New.

HTML/CSS Rendering ❌ ✅ ✅ If email messages don't appear correctly, use Outlook New or Web.
External content / “Show blocked content” (images) ✅ (global Trust Center control + per‑message download) ❌ (no equivalent global control; Safe Senders / per‑message only) ⚠️ (per‑message + Safe Senders only) Classic allows global enable/disable of blocked content behavior; New/OWA require per-message or Safe Sender trust
Trust Center / advanced client security controls ✅ ❌ na Trust Center model largely absent in New; controls simplified or removed

NOTES:

  • Classic Outlook remains on the computer, even after a migration to Outlook (new).
  • Both Outlook classic and new can exist and run on a computer at the same time. There’s no conflict.
  • Outlook (classic) for Windows will remain supported until at least 2029.
  • Change to Outlook (new) when YOU are ready, not when Microsoft tries to force you.

Sources