IMAP4 by design keeps your emails on the server. POP3 accounts can be configured to leave copies on the server.
Post Office Protocol version 3 (POP3) is a protocol used by email clients to retrieve emails from a mail server. It operates on port 110 and typically downloads emails from the server to the client's device.
POP (post office protocol) is usually used to retreive emails from a server.
POP is Post Office Protocol. It is a protocol used by email clients to retrieve emails from a remote server.
The IMAP protocol differs from the POP3 protocol is that the IMAP doesnt require the user to download all the emails to the PC to check for new emails. It is also much easier to distinguish between read and unread emails while using the IMAP as oppose to the POP3. Some other difference is the IMAP is that you can create multiple email accounts from the PC where as the POP3 requires new email accounts to be created on the server. Another difference is that with IMAP emails can be deleted directly through the server where as the POP3 emails are deleted on the PC.
IMAP and bearheads
GC
RDP
PHP allows you to send emails via your server. This is most commonly done with the mail function, though more efficient alternatives exist like the pear Mail package. Keep in mind that if you have not configured PHP (and your server) to send emails, none of those functions will work.
HTTP, not FTP, FTP allows you to download files, HTTP allows you to view.
pop & imap
An Xtramail account allows you to store the last 30 days worth of emails received by your account on a separate server, so that if your email server goes down you can still access your emails anywhere.
There is no single protocol used between a server and a client; the protocol depends on what the server and client are doing and how they are currently communicating.