When an email is sent to you, it travels from the sender, to their mail server, to your mail server, and finally to you. The protocol used for that last leg — getting from your mail server to your email client — matters a lot. Here's a breakdown of the three most common options:
POP3
POP3 downloads your email to a single device and then deletes it from the server. Because the email lives only on the device that downloaded it, it isn't available anywhere else. If you read email on your laptop, it won't appear on your phone. POP3 has become largely obsolete for this reason and is only really seen today in setups that have been in place for 10+ years without change.
IMAP
IMAP stores all email on the server. Your client displays what's on the server, and changes sync automatically across all your devices. Read a message on your phone — it's read on your laptop too. Delete it on one — it's gone everywhere. IMAP is the right choice for most businesses using email across multiple devices.
Exchange
Exchange is Microsoft's proprietary protocol. It does everything IMAP does, but also syncs your contacts and calendar across devices. It's more comprehensive but also more expensive and requires Outlook as your client. It's the right choice if cross-device calendar and contact sync is critical to your workflow.
Hyperion Works provides all three hosting options. If you want help deciding what's right for your business, give us a call.