If you’ve ever set up an email account manually, you may have come across the term POP, or more specifically POP3, listed as one of the protocol options alongside IMAP. While most people never need to think about this technical detail thanks to modern email apps handling it automatically, understanding what POP actually is can be useful, particularly if you’re troubleshooting email issues or setting up a new account manually.
POP stands for Post Office Protocol, and POP3 refers to version 3 of this protocol, which has been the standard version in use for many years. It’s one of the internet protocols used specifically for retrieving email from a mail server, and it works in a fairly straightforward way: when your email app connects to the server using POP3, it downloads your messages directly onto your device and, in many default configurations, removes them from the server afterwards.
This download-and-remove approach made a lot of sense when POP3 was first widely adopted, back when most people accessed email from a single computer and storage space, both on servers and on personal devices, was much more limited than today. By downloading emails onto your local device and clearing them from the server, POP3 helped manage server storage constraints while still giving users full access to their messages.
However, this same behaviour is also POP3’s biggest limitation in the modern world, where most people check email across multiple devices, such as a phone, a laptop, and a work computer. If POP3 downloads and removes messages from the server after retrieving them on one device, that same email might not appear when you check your inbox from a different device, since it’s already been removed from the server. Many modern email providers configure POP3 to leave a copy on the server for a period of time to reduce this issue, but it remains fundamentally less suited to multi-device use than the alternative protocol, IMAP.
IMAP, or Internet Message Access Protocol, is the modern standard most email providers and apps now use by default. Rather than downloading and removing emails, IMAP keeps messages stored on the server and simply syncs what your device displays with what’s actually on the server. This means that whether you check your email on your phone, laptop, or through a web browser, you’ll see the same messages, folders, and read/unread status everywhere, since everything stays synchronised with the central server copy.
Given these differences, POP3 has become less commonly used for everyday personal email, since most people expect their inbox to be accessible and consistent across multiple devices. However, POP3 still has some legitimate use cases. It can be useful for archiving email locally, for accounts with very limited server storage where you want messages downloaded and removed to free up space, or in certain business and technical setups where a single-device download approach is actually preferred for backup or security reasons.
When manually configuring an email account, you may still be asked to choose between POP3 and IMAP as part of the setup process, alongside settings like server addresses and ports. For the vast majority of everyday users who check email from more than one device, IMAP is generally the better choice, while POP3 remains a specialised option for specific archiving or single-device scenarios.
In short, POP, specifically POP3, is an older internet protocol used for downloading email from a server to a single device, historically useful for saving server space but largely superseded by IMAP for most everyday, multi-device email use today.
If you’re setting up a new email account and aren’t sure which protocol to pick, checking your provider’s recommended settings is the safest route, since most modern webmail services default to IMAP automatically and only offer POP3 as an advanced, optional configuration.