Understanding POP3 and IMAP


Zoho Mail offers multiple ways to access your email accounts from different service providers within the Zoho mailbox. Email protocols like IMAP and POP are application layer protocols, providing the ability to fetch emails from one server to another. They work by establishing a TCP link. Understanding and knowing the difference between IMAP and POP will help you in choosing the right protocol to facilitate your requirements. 





Understanding the Protocols 

After receiving the emails from the email server, Post Office Protocol - Version 3 (POP3) stores them in the physical device you configure POP in.

Internet Message Access Protocol (IMAP) lets you access the emails from your email server, it stores those emails in the remote server.

Persisting email copies

POP can be understood precisely as its name suggests. Just how a post office would deliver the mail to its recipient and not store a copy, POP will download emails from the server and not store a copy, unless ‘keep a copy on the server is selected.

IMAP, on the other hand, will save a copy automatically without any manual configuration. Whenever you try to access your IMAP account, your mailbox will communicate with the server and retrieves the emails.

Device limit

There is no limit to the number of devices you can configure POP. But keep in mind, only the downloaded copies of emails will get displayed, if ‘keep a copy on the server’ is not selected.

There is no limit to the number of devices you can configure IMAP.


POP does not support synchronization. Any changes you made to the emails locally will not get reflected at the source mailbox and vice versa. IMAP accounts support real-time synchronization with the source account. The changes made in your IMAP account will get reflected in the source account and vice versa. Given that IMAP can be used in more than one device, all the devices you configured IMAP will get synced of the changes.

Offline accessibility

Because POP downloads the emails and stores in the device, all the emails can be accessed without the internet.All the emails of an IMAP account are stored in the server. This required an active internet to access your emails. 


POP with SSL secure server listens on port 995.IMAP with SSL secure server listens on port 993.


Once downloaded, it's much easier to access your POP emails as they are available in your local device.Having to connect and sync the data with the server every time you need to access your mailbox, IMAP may be slower compared to POP.

IMAP and POP cater to the needs of people with different requirements. If you are someone who only accesses email at a single device and doesn't have continued active internet access, POP may be the protocol to go with. But if you use multiple mailboxes and can't worry about keeping track of emails at a single device, IMAP may be the one. 

Still can't find what you're looking for?

Write to us: support@zohomail.com