Use IMAP unless you have a reason not to. IMAP keeps your mail on your provider's server and syncs what you do, so your phone, your computer and webmail match. POP3 downloads new mail to one device; most apps can leave a copy on the server, but mail you read, file or delete there stays that way only on that device, and your sent mail stays on it too.
The difference
POP3 (Post Office Protocol) was made for one computer: collect new mail, then remove it from the server (RFC 1939). IMAP (Internet Message Access Protocol) was made for mail that lives on the server, with folders, flags and many devices.
| IMAP | POP3 | |
|---|---|---|
| Where mail lives | On the server, with copies on your devices | On the device that downloaded it |
| Several devices | All show the same mail | Each downloads its own copy, or only one gets it |
| Read, moved and deleted mail | Changes everywhere | Changes on that device only |
| Folders | Synced | Only the inbox is collected |
| Sent mail | Saved on the server | Saved on that device |
| Ports | 993 (SSL/TLS), 143 (STARTTLS) | 995 (SSL/TLS), 110 (STARTTLS) |
When POP3 still makes sense
- You read mail on one computer only, and want it all kept there.
- Your provider's storage is small, and you'd rather keep old mail on your own disk.
- An old app or device only speaks POP3.
Which providers offer POP3
All 23 providers we list offer IMAP. Our guides list POP3 for these 13, from their own help pages; others may offer it too.
| Provider | POP3 server | Port | Security |
|---|---|---|---|
| AT&T Mail | inbound.att.net | 995 | SSL/TLS |
| BT Email | mail.btinternet.com | 995 | SSL/TLS |
| CenturyLink Email | pop.centurylink.net | 995 | SSL/TLS |
| DreamHost Email | pop.dreamhost.com | 995 | SSL/TLS |
| EarthLink Email | pop.earthlink.net | 995 | SSL/TLS |
| Hostinger Email | pop.hostinger.com | 995 | SSL/TLS |
| IONOS Mail | pop.ionos.com | 995 | SSL/TLS |
| mail.com | pop.mail.com | 995 | SSL/TLS |
| Namecheap Private Email | mail.privateemail.com | 995 | SSL/TLS |
| Optimum Email | mail.optimum.net | 995 | SSL/TLS |
| Rackspace Email | secure.emailsrvr.com | 995 | SSL/TLS |
| Verizon email (in AOL Mail) | pop.verizon.net | 995 | SSL/TLS |
| Xfinity Email | pop3.comcast.net | 995 | SSL/TLS |
Each guide has the IMAP and SMTP servers beside the POP3 one.
Switching from POP3 to IMAP
- Look for mail that's only on your computer: if the POP3 app removed messages from the server after downloading them, they're nowhere else.
- Add the account again in your mail app, this time as IMAP, with your provider's IMAP settings.
- Drag the old messages from the POP3 account into a folder of the IMAP account. The app uploads them, and they appear on every device.
- Remove the POP3 account once everything's there.
LocalInbox and POP3
LocalInbox reads every account over IMAP and sends over SMTP; it doesn't use POP3. It keeps the mail it has synced on your Mac, so you still get offline reading and fast search, without POP3's one-device limits.
Sources
What this page says about the protocols comes from their standards, checked in November 2026. The providers' numbers are counted from our settings guides, each checked against the provider's own help pages, and what it says about LocalInbox comes from the app.
Questions
Is IMAP better than POP3?
For most people, yes: it keeps every device in step and keeps your mail safe on the server if a computer is lost. POP3 suits mail read on one computer and kept there.
Can I use POP3 and IMAP on the same account?
Usually, yes, if your provider offers both. If the POP3 app is set to remove mail from the server after downloading it, though, that mail disappears from your IMAP devices.
Does POP3 sync sent mail?
No. POP3 only collects new mail from the inbox. What you send from a POP3 app is saved on that device.
Does LocalInbox support POP3?
No. LocalInbox reads every account over IMAP and sends over SMTP; it doesn't use POP3. Every provider we list offers IMAP: https://localinbox.app/imap-settings