# Migrate email from Exchange Server to Microsoft 365

> Yes. You can move every email from Exchange Server to Microsoft 365 without losing folders, read status or dates. Connect both mailboxes over IMAP and IMAP Migrator copies the messages server to server, leaving the source mailbox untouched. Small mailboxes finish in minutes; a 5 GB mailbox usually takes one to three hours.

## At a glance

- From: Exchange Server (on-premises), `ews:mail.company.com:443` (SSL)
- To: Microsoft 365, `outlook.office365.com:993` (SSL)
- Copied: every folder, read and flagged state, received dates; duplicates are skipped.
- The source mailbox is opened read-only.

## Step by step

1. **Prepare Exchange Server**: Choose "Exchange Server 2013–2019 (EWS)" as the source provider: mail is read over Exchange Web Services, so IMAP does not have to be switched on. Sign in with user@domain or DOMAIN\user and the Windows password. The server name is the one in the Outlook on the web address (for example mail.company.com). EWS must be reachable from the internet over HTTPS, as it is for Outlook on phones. Shared and room mailboxes: grant the migration account Full Access, then add them with the account's password. Calendars and contacts are copied in a separate run from the Calendars & contacts page, also over EWS.
2. **Prepare Microsoft 365**: Create the users and assign licences with Exchange Online before you start. Enable IMAP on each mailbox (Exchange admin center → Manage email apps). Microsoft throttles IMAP uploads; 2 to 4 accounts in parallel usually runs fastest. Microsoft turned off password logins for IMAP, so use "Sign in with Microsoft" in the console. The mailbox must have IMAP enabled.
3. **Enter the servers and accounts**: In the console, use ews:mail.company.com as the source and outlook.office365.com as the target (port 993, SSL). Add the accounts one per line (email, then password) or upload a CSV. To let each person type their own password, send invitation links instead.
4. **Validate and estimate**: "Validate accounts" tries every login; "Estimate size and time" shows the message count, total size and free space on the target.
5. **Launch and watch**: Start the migration and follow progress per account and folder with a live action log. Copied messages are never copied twice, and an interrupted run continues where it stopped.
6. **Switch MX**: After the first copy, point the MX record to the new provider and press "Final sync" to bring over mail that arrived in between.

## Good to know about Exchange Server

- Exchange Server can be the source only.
- Public folders are not copied.

## Good to know about Microsoft 365

- Sent, Drafts, Trash and Junk are mapped to Sent Items, Drafts, Deleted Items and Junk Email automatically.
- Messages above the mailbox size limit (35 MB by default, up to 150 MB) are refused and listed as failed.

## FAQ

**Will my email be deleted from Exchange Server?** No. The source is opened read-only; messages are copied and even their read state stays the same.

**Are folders, read status and dates kept?** Yes. Every folder, the read and flagged state and the received date are copied as they are. Sent, Drafts, Trash and Junk are mapped to the target's own folders.

**How long does it take?** Small mailboxes finish in minutes; a 5 GB mailbox usually takes one to three hours.

**Can I move many mailboxes at once?** Yes. Add hundreds of mailboxes as a list or CSV and several run in parallel. If you do not want to collect passwords, send invitation links so each person types their own.

**Are calendars and contacts moved too?** Yes. Calendars and contacts are copied in a separate run: through Google and Microsoft 365 sign-in, and over CalDAV/CardDAV for other providers.

**What does it cost?** You pay for days of access: pick a day, a week or a month and move unlimited accounts and messages in that time. There is a free trial for one small mailbox.

Start here: https://whatsmyip.tr/login.html?mode=register