A cloud-based service included in Microsoft 365, delivering scalable messaging and collaboration features with simplified management and automatic updates.
One clarification that trips up almost every SBS shop making this move, because the two answers above are correct but answer a different question: Exchange 2019 (and Exchange Server SE) has a POP3 service. It lets Outlook or a phone read an Exchange mailbox over POP3 (POP3 and IMAP4 in Exchange Server). It does not have a POP3 connector that fetches mail from your ISP's mailboxes into Exchange. That connector was part of SBS 2008 and SBS 2011 only; standalone Exchange never had it.
So after the migration you have two choices: point your domain's MX record at the new Exchange server (static IP, open port 25, reverse DNS and a filter in front - the cleaner design), or keep the ISP mailboxes and run a separate connector service that polls them and submits to Exchange over SMTP, which is the SBS model continued. I'm the founder of Servolutions and we make one of those connectors (POPcon), so I'll leave the product part at that; the decision above is the one that matters, and the MX route is genuinely the better one if you have the prerequisites.
