Migrate from Microsoft 365 (Bulk)

This guide covers migrating multiple Microsoft 365 (formerly Office 365) or Outlook.com accounts to TrekMail at once.

Before you start

If accounts have multi-factor authentication (MFA) enabled, each user needs an App Password.

Generate App Passwords (per user, if MFA is on)

1. Sign in at account.microsoft.com/security.
2. Go to Additional security options > App passwords.
3. Create a new App Password and copy it.

If MFA is not enabled, the regular account password works for IMAP.

Prepare your CSV

All Microsoft 365 accounts use the same IMAP server, so use the simple 3-column format:

source_email,source_password,destination_email
alice@company.onmicrosoft.com,app-pw-1,alice@yourdomain.com
bob@company.onmicrosoft.com,app-pw-2,bob@yourdomain.com
carol@company.com,app-pw-3,carol@yourdomain.com

Select Outlook as the provider in the form — the IMAP host (outlook.office365.com, port 993, SSL) is filled in automatically.

Run the bulk import

1. Go to Import > Bulk Import tab.
2. Select Outlook as the provider.
3. Paste your CSV or upload the file.
4. Click Preview & Validate, then Start Migration.

What to expect

• Outlook folder names (Sent Items, Deleted Items, Junk Email) are automatically mapped to standard names.
• Microsoft 365 allows generous IMAP concurrency, so migrations tend to run faster than Gmail.

Common issues

• "Authentication failed" — If MFA is enabled, you must use an App Password. Regular password will be rejected.
• Shared mailboxes — Shared/resource mailboxes may need additional permissions. Migrate them individually if bulk fails.