IMAP keeps messages on the server and synchronizes folders, flags, and read state across every device and client. POP3 downloads messages to a single device and, by default, removes them from the server. For any modern business mailbox that multiple people or devices must access, IMAP is the correct protocol.
The core difference that matters for teams
Both protocols retrieve mail, but they solve different problems from different eras.
- IMAP (Internet Message Access Protocol) treats the server as the source of truth. Messages stay on the server. Clients download headers or full bodies as needed, and any change—read, flagged, moved, deleted—propagates to every other connected client.
- POP3 (Post Office Protocol version 3) treats the server as a temporary holding area. A client connects, downloads messages, and (unless “leave messages on server” is enabled) deletes them from the server. The local device becomes the only complete copy.
That single design choice drives everything else: multi-device use, shared inboxes, search, backups, and offboarding.
Why IMAP wins for business mailboxes
Business email is almost never single-device. A founder checks mail on a laptop, phone, and tablet. Support staff share a role address. An offboarded employee’s archive must remain searchable. IMAP supports all of these without workarounds.
Multi-device synchronization
When a message is read on a phone, it appears read on the desktop client. Folders created in one place appear everywhere. This is the expected behavior of every modern provider, including ArawaMail’s web mailbox and any IMAP client you connect.
Server-side storage and search
Mail stays on the server until you deliberately delete or archive it. Server-side search, spam filtering, and retention policies remain possible. With POP3 the server often has only the newest messages or none at all.
Shared and role-based addresses
Addresses such as support@, billing@, or hello@ need a single authoritative inbox. IMAP lets multiple people (or an AI agent with a mailbox) see the same state. POP3 would require every user to leave messages on the server and hope their clients do not conflict.
Clean offboarding and compliance
When someone leaves, the company keeps the mailbox. An administrator can open it, reassign it, or export it. With POP3 the mail may already live only on a departed laptop.
When POP3 still appears (and why to avoid it)
POP3 survives in a few narrow cases: extremely limited local storage, strict offline-only workflows, or legacy systems that never implemented IMAP. Even then, most clients can be set to “leave messages on server,” which turns POP3 into a poorer version of IMAP.
For new business setups the recommendation is unambiguous: choose IMAP. Providers that still push POP3 as the default are optimizing for the wrong decade.
How ArawaMail implements mailbox access
ArawaMail mailboxes are designed for IMAP. The documented client settings are:
- Incoming (IMAP): host
imap., port 993, SSL/TLS, full email address as username. - Outgoing (SMTP): host
smtp., port 465, SSL/TLS, same credentials.
Users can also open the mailbox directly in the browser. Messages sent through the HTTP API appear in the Sent folder, keeping the web and IMAP views consistent. See the Connect a Device guide for exact hostnames once your domain is active.
Migration considerations
Moving from a POP3-only host usually means the historical mail already lives on individual devices. Plan an export/import step (or a temporary “leave on server” period) before switching MX records. Once the domain points at a modern host that supports IMAP, new mail arrives correctly and clients can be reconfigured in minutes.
If you are consolidating both human inboxes and product/transactional mail onto one organizational domain, start with the business-email setup on ArawaMail and keep the same domain identity for the API. Related reading: custom-domain business email vs Gmail and keeping inboxes and product email on one domain.
How we analyzed the choice
The comparison rests on the protocol specifications themselves (IMAP keeps server state; POP3 is download-centric), observed client behavior across Outlook, Apple Mail, Thunderbird, and mobile apps, and the operational requirements of shared inboxes, multi-device teams, and clean offboarding. ArawaMail’s own documentation prioritizes IMAP + SMTP over TLS and does not surface POP3 as a supported access method for production mailboxes.
FAQ
Can I use both IMAP and POP3 on the same mailbox?
Technically some servers allow it, but the results are messy. One client downloading and deleting via POP3 will break the IMAP view for everyone else. Stick to IMAP.
Does IMAP require constant internet?
Clients cache messages and folders for offline reading. Changes sync when the connection returns. Full-text server search still needs the network.
Is POP3 more private because mail leaves the server?
No. Once mail is on a laptop it is subject to that device’s security. Server-side encryption, access logs, and retention policies are usually stronger on a well-run host than on individual endpoints.
What ports should I open?
IMAP over TLS uses port 993. SMTP submission commonly uses 465 (implicit TLS) or 587 (STARTTLS). Port 25 is for server-to-server relay, not client access.
For teams that need both reliable human inboxes and a transactional API on the same domain, start with ArawaMail business email and connect clients via IMAP. The protocol decision is settled; the remaining work is DNS, authentication, and clear ownership of every address.