Glossary
IMAP vs POP3: What's the Difference?
IMAP syncs; POP3 downloads. Both are protocols a mail app uses to fetch email from a server, but IMAP keeps the mailbox on the server — every device sees the same folders, and reading or deleting on one syncs everywhere. POP3 pulls messages down to one device and, in its default setup, removes them from the server.
The practical differences
| IMAP | POP3 | |
|---|---|---|
| Mail lives | On the server | On one device |
| Multiple devices | Same view everywhere | Out of sync |
| Folders | All of them | Inbox only |
| Read/answered state | Synced | Local only |
| Port (SSL/TLS) | 993 | 995 |
The "Inbox only" line surprises people: POP3 has no concept of folders. It fetches the inbox, so anything archived or filed into folders never comes down at all.
Which should you use?
IMAP, almost always — it's what phones and multi-device life assume, and it's what the setup screens of Gmail, Yahoo, and iCloud expect today. POP3 earns its keep in one niche: draining mail off a small server quota onto a single machine that becomes the system of record.
Neither one is a backup
A synced mailbox is not a saved mailbox. IMAP mirrors deletions faithfully — a message deleted, purged, or lost with the account disappears from every synced client too. What IMAP is good for is making a backup: sync the account into a desktop client, then export. That's the history-capturing method in our guides for Gmail, Yahoo Mail (mind the app-password catch), and iCloud — and the methods comparison shows where an IMAP export fits next to a forwarding-based archive that runs by itself.
FAQ
Should I use IMAP or POP3?
IMAP, unless you have a specific reason not to. It keeps mail on the server, syncs state across all your devices, and covers every folder. POP3 suits exactly one scenario: downloading mail to a single computer, for example to drain a small server quota.
Does POP3 delete my email from the server?
By default most clients remove messages from the server after downloading them, though nearly all offer a "leave a copy on the server" option, often with a delete-after-N-days setting. Check that setting before trusting POP3 with anything you'd miss.
What ports do IMAP and POP3 use?
IMAP uses port 993 with SSL/TLS (143 unencrypted or STARTTLS). POP3 uses port 995 with SSL/TLS (110 unencrypted). Outgoing mail is a separate protocol entirely — SMTP, on port 465 or 587.
Is IMAP a backup of my email?
No. IMAP is synchronization: every client mirrors the server, deletions included, and everything still hangs off one account. A backup is an independent copy somewhere else — made by exporting from a synced client, or by archiving each message to your own storage as it arrives.
Related terms
Email headers · MBOX · RFC 822