Analyze a Outlook / Microsoft 365 mailbox
Get detailed statistics about your Outlook / Microsoft 365 mailbox, no account needed, with the right IMAP settings already set up.
IMAP server and port already filled in for Outlook / Microsoft 365 — all that's left is to enter your credentials.
IMAP settings for Outlook / Microsoft 365
Outlook / Microsoft 365
- IMAP server
- outlook.office365.com
- Port
- 993
- Encryption
- SSL/TLS
- App password
- Required
Microsoft has disabled basic IMAP authentication on most personal and work accounts: an app password (or reconnecting via modern authentication) is required as soon as two-factor authentication is enabled.
App password for Outlook / Microsoft 365: Generate an app password from your Microsoft account security settings if two-factor authentication is on.
How it works
- Enter the credentials for your Outlook / Microsoft 365 mailbox — the server (outlook.office365.com, port 993) is already filled in.
- Start the analysis — MailSync connects to your Outlook / Microsoft 365 mailbox read-only.
- Review the resulting statistics — size per folder, most frequent senders, breakdown by year.
What this tool doesn't do
- The operation only works over IMAP: a mailbox reachable only via POP3, or through a closed proprietary connector, can't be used.
- MailSync doesn't read the content of your Outlook / Microsoft 365 messages: it's limited to headers (sender, date, size).
Frequently asked questions
Do I need an app password for Outlook / Microsoft 365? +
Yes. Generate an app password from your Microsoft account security settings if two-factor authentication is on. Microsoft has disabled basic IMAP authentication on most personal and work accounts: an app password (or reconnecting via modern authentication) is required as soon as two-factor authentication is enabled.
Is my Outlook / Microsoft 365 account changed during the analysis? +
No. The connection to Outlook / Microsoft 365 is read-only: no message is deleted, moved, or marked as read. MailSync only looks at technical headers (sender, date, size) to build statistics, without ever opening the body of an email.
Is there a volume limit to analyze my Outlook / Microsoft 365 mailbox? +
No, the analysis is entirely free regardless of the volume of your Outlook / Microsoft 365 mailbox, with no account required.
Are my Outlook / Microsoft 365 credentials stored? +
No. Your IMAP credentials are encrypted with libsodium for the duration of the operation, then erased as soon as it finishes. If you're signed in to your MailSync account and choose to save the mailbox, only that one is kept (encrypted); you can delete it at any time.