IMAP vs POP vs Exchange
Picking the wrong access protocol gives the wrong tradeoffs (sync, storage, offline, multi-device). This page lays them out side-by-side.
| Protocol | Sync | State | Offline | Best for |
|---|---|---|---|---|
| POP3 | Download-only | Client-side | Full (deleted from server after download) | Single-device archive use |
| IMAP | Two-way | Server-side | Cache available, full sync requires explicit selection | Multi-device, free / personal mail |
| Exchange ActiveSync (EAS) | Two-way + push | Server-side | Cache + offline send queue | Mobile devices with corporate Exchange |
| Exchange Web Services (EWS) | Two-way + push | Server-side | Full client-controlled | Desktop / programmatic Exchange access (deprecated; migrate to Graph) |
| Microsoft Graph | API (request/response) | Server-side | Whatever your app implements | Programmatic Microsoft 365 access (modern standard) |
Compares IMAP, POP3, Exchange ActiveSync, EWS, and Microsoft Graph across sync behavior, server-side state, offline access, attachment handling.
Configuring a mail client. Building anything that reads from a mailbox programmatically.
FAQ
Should I still use POP3?+
Only if you want single-device, download-and-delete behavior. For everything else, IMAP or Graph.
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Articles, glossary entries, and other tools on the same topic.
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