What protocols do email clients typically require to send mail?

Email clients usually require the SMTP protocol to send emails. SMTP is a protocol that provides reliable and efficient email transmission. SMTP is an email service built on the FTP file transfer service. It is mainly used to transfer email information between systems and provide notifications about incoming letters.

Mail clients usually refer to software that uses protocols such as IMAP/APOP/POP3/SMTP/ESMTP to send and receive emails. Users do not need to log in to the mailbox web page to send and receive emails.

There are also some mail service providers that provide services for collecting third-party mail, such as QQ mailbox, 163 mailbox, etc., which are also carried out through the above protocol. For the target mail server, such operations are also equivalent. Send and receive emails on the client.

POP3 and IMAP protocols are common protocols for receiving emails.

SMTP is a common protocol for sending emails.

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