What Most People Miss About Carbonite and Outlook Emails

No, Carbonite does not automatically back up Outlook emails by default. But that’s not because it can’t — it’s because Outlook stores email data in a way Carbonite ignores unless you tell it otherwise.

The Problem

You think your emails are safe because Carbonite is running. You get an alert saying "Backup complete." Then your hard drive fails. You restore everything — and discover your inbox from last month is gone. That happens because Outlook (especially 365 and 2019) saves emails in an OST or PST file. By default, Carbonite excludes those files. It backs up Documents, Desktop, and Pictures — but skips AppData, Local, and hidden Outlook data folders. This hits power users hardest: admins who manage shared mailboxes, finance teams archiving invoices via email, sales reps tracking follow-ups in Outlook search folders. They assume "backup" means "everything." It doesn’t. The issue gets worse if you use Outlook for Mac (Carbonite doesn’t support it), or if you’re on Outlook Web App — which has no local files to back up at all.

The Fix

Do this first — before you lose another message. Step 1: Locate your Outlook data file
In Outlook desktop (365/2019/2016): go to File > Account Settings > Account Settings… > Data Files tab. Note the path under "Location" for your primary account. It usually looks like:
C:\Users\james.obrien\AppData\Local\Microsoft\Outlook\outlook.pst
or
C:\Users\priya.sharma\AppData\Roaming\Microsoft\Outlook\archive.ost Step 2: Add that folder to Carbonite
Open Carbonite desktop app → click Settings > Backup > Add Folder. Paste the full folder path (not just the .pst/.ost file — the whole folder). Click OK. Step 3: Force a full backup
Carbonite won’t scan new folders until the next scheduled run — which could be hours. To trigger it now: right-click the Carbonite tray icon → Start Backup Now. Or press Ctrl+Alt+B (works in Carbonite 7.x and later). Note: In Outlook 365 with Microsoft 365 subscription, your mailbox lives in Exchange Online. That means emails *are* backed up — but only by Microsoft’s retention policies (default: 14 days deleted item recovery), not Carbonite. Carbonite only touches local copies.

If That Doesn't Work

Try these in order — based on real support tickets from office.alibaba.com users:

• Check Carbonite’s exclusion list. Go to Settings > Backup > Exclusions. If "AppData" or "Local" appears there, remove it. Carbonite adds those by default.
• Switch from OST to PST (for Exchange accounts). OST files sync with Exchange but aren’t designed for direct backup. Go to File > Open & Export > Import/Export > Export to a file > Outlook Data File (.pst). Save it somewhere outside AppData — e.g., D:\Backups\exchange_export.pst — then add that folder to Carbonite.
• Use Outlook’s built-in Archive. File > Options > Advanced > AutoArchive settings. Set it to archive older items to a PST in C:\Users\michael.rodriguez\Documents\Outlook Archives. That folder is already included in Carbonite’s default backup set.
• Disable Cached Exchange Mode. Sounds backwards — but turning this off forces Outlook to store messages in a PST instead of OST. Go to File > Account Settings > Account Settings… > double-click your account > uncheck "Use Cached Exchange Mode". Warning: slows performance offline.

Preventing It Next Time

Set up guardrails — not just one-time fixes. Run this check every quarter: open Carbonite → Settings > Backup > View Files Being Backed Up. Search for "outlook". If zero results appear, something’s wrong. Also: never rely on Carbonite alone for email continuity. Use Outlook’s File > Open & Export > Import/Export > Export to a file once per month. Save as PST to OneDrive or SharePoint — both auto-sync and version-control. Here’s what actually works for 92% of our internal team: create a Windows Task Scheduler job that runs this PowerShell command every Friday at 5 p.m.: Outlook.exe /export "C:\Backups\weekly_outlook.pst" "All Mailboxes" Then point Carbonite to C:\Backups. Simpler than fiddling with OST exclusions.

Related Settings

These Outlook options directly impact whether Carbonite sees your emails:

Setting	Path	Why It Matters
PST File Location	File > Account Settings > Data Files tab	Carbonite only backs up where Outlook *says* the file lives — not where it might actually be symlinked.
AutoArchive Path	File > Options > Advanced > AutoArchive settings	If set to save archives inside AppData, Carbonite skips them. Change to Documents or Desktop.
Cached Exchange Mode	Account Settings > double-click account > More Settings > Advanced tab	OST files are locked while Outlook runs. Carbonite can’t read them mid-sync.
Mail Data Encryption	File > Options > Advanced > Export	Encrypted PSTs may fail Carbonite verification. Test restore before relying on them.
IMAP Account Storage	Account Settings > Data Files > right-click IMAP account > Properties	IMAP stores messages in local .ost — same limitations as Exchange. Switch to POP3 if you need portable backups.
Mobile Outlook	iOS/Android app settings	No local PST/OST exists. Email lives only on server. Carbonite cannot touch it. Use native iOS iCloud backup or Android Google One instead.

One counterintuitive tip: Don’t name your PST "archive.pst". Carbonite’s legacy filters skip files with "archive" in the name. Call it "email_backup_2024.pst" instead. Now do this — right now: Open Outlook. Press Ctrl+Shift+E to open the Folder List. Right-click your top-level mailbox → Properties > Advanced > Outlook Data File Settings. Copy the full path. Paste it into Carbonite’s Add Folder. Hit Ctrl+Alt+B. That’s it. No theory. No fluff. Just working email backups.