一、電子郵件和電子郵箱一樣嗎
電子郵件和(he)電(dian)(dian)子(zi)(zi)(zi)(zi)郵箱兩個概念是(shi)(shi)不同(tong)的(de),電(dian)(dian)子(zi)(zi)(zi)(zi)郵件是(shi)(shi)一種用(yong)電(dian)(dian)子(zi)(zi)(zi)(zi)手段(duan)提供信息交換的(de)通(tong)信方式,而電(dian)(dian)子(zi)(zi)(zi)(zi)郵箱是(shi)(shi)通(tong)過網(wang)(wang)絡電(dian)(dian)子(zi)(zi)(zi)(zi)郵局為(wei)網(wang)(wang)絡客戶(hu)提供的(de)網(wang)(wang)絡交流電(dian)(dian)子(zi)(zi)(zi)(zi)信息空間。
電子郵箱是電子郵件的載體,用來管理和收發電子郵件。而電子郵件是電子郵箱的內容,也是電子郵箱的重要組成部分。電子郵件和電子郵箱是完全不可分割的整體。以最簡單例子來說,電子郵件就像我們以前的信件,電子郵箱就像我(wo)們以前的信箱(xiang),用來投遞(di)信件(jian)以及接收信件(jian)用的。
二、電子郵件的工作原理是什么
1、電子郵件(jian)系統是一種新型的信息(xi)系統,是通(tong)信技術(shu)和計算機技術(shu)結合的產物。
電子(zi)郵件的(de)傳輸是通過電子(zi)郵件簡單傳輸協議(Simple Mail Transfer Protocol,簡稱(cheng)SMTP)這一系統軟件來完(wan)成(cheng)的(de),它是Internet下的(de)一種電子(zi)郵件通信協議。
2、電(dian)(dian)子郵件的基本原理是在通信(xin)網(wang)上(shang)設立“電(dian)(dian)子信(xin)箱系(xi)統(tong)”,它實(shi)際上(shang)是一個(ge)計算機系(xi)統(tong)。
系(xi)(xi)統的(de)(de)(de)硬(ying)件是一個高性能、大容量的(de)(de)(de)計算機(ji)。硬(ying)盤(pan)作(zuo)為信(xin)(xin)箱(xiang)(xiang)的(de)(de)(de)存儲(chu)介質,在硬(ying)盤(pan)上(shang)為用(yong)戶(hu)(hu)分(fen)一定的(de)(de)(de)存儲(chu)空間作(zuo)為用(yong)戶(hu)(hu)的(de)(de)(de)“信(xin)(xin)箱(xiang)(xiang)”,每位用(yong)戶(hu)(hu)都有屬于自己(ji)(ji)的(de)(de)(de)—個電子信(xin)(xin)箱(xiang)(xiang)。并確(que)定—個用(yong)戶(hu)(hu)名和用(yong)戶(hu)(hu)可以(yi)自己(ji)(ji)隨意修改的(de)(de)(de)口令。存儲(chu)空間包含存放所收信(xin)(xin)件、編(bian)輯信(xin)(xin)件以(yi)及信(xin)(xin)件存檔(dang)三部分(fen)空間,用(yong)戶(hu)(hu)使用(yong)口令開(kai)啟自己(ji)(ji)的(de)(de)(de)信(xin)(xin)箱(xiang)(xiang),并進行發信(xin)(xin)、讀信(xin)(xin)、編(bian)輯、轉發、存檔(dang)等各種操作(zuo)。系(xi)(xi)統功能主要由軟件實現。
3、電子郵件的通(tong)信(xin)是在信(xin)箱之(zhi)間進行的。
用(yong)戶首先開啟自己的(de)信箱(xiang),然后通過鍵入命(ming)令的(de)方(fang)(fang)式(shi)將需要發(fa)送的(de)郵(you)件發(fa)到對方(fang)(fang)的(de)信箱(xiang)中。郵(you)件在信箱(xiang)之間進(jin)行(xing)傳(chuan)(chuan)遞和(he)交(jiao)換,也可以(yi)與另—個郵(you)件系統進(jin)行(xing)傳(chuan)(chuan)遞和(he)交(jiao)換。收方(fang)(fang)在取信時,使(shi)用(yong)特(te)定帳號(hao)從信箱(xiang)提取。
電(dian)(dian)子郵(you)(you)件(jian)(jian)的(de)(de)工作(zuo)過(guo)程(cheng)遵循客(ke)戶(hu)(hu)-服(fu)(fu)務(wu)(wu)(wu)(wu)器(qi)(qi)(qi)模式。每份電(dian)(dian)子郵(you)(you)件(jian)(jian)的(de)(de)發送(song)都(dou)要涉及到(dao)(dao)發送(song)方(fang)(fang)(fang)與接(jie)(jie)收(shou)(shou)(shou)方(fang)(fang)(fang),發送(song)方(fang)(fang)(fang)構成(cheng)客(ke)戶(hu)(hu)端,而(er)接(jie)(jie)收(shou)(shou)(shou)方(fang)(fang)(fang)構成(cheng)服(fu)(fu)務(wu)(wu)(wu)(wu)器(qi)(qi)(qi),服(fu)(fu)務(wu)(wu)(wu)(wu)器(qi)(qi)(qi)含有(you)眾多(duo)用戶(hu)(hu)的(de)(de)電(dian)(dian)子信箱。發送(song)方(fang)(fang)(fang)通(tong)過(guo)郵(you)(you)件(jian)(jian)客(ke)戶(hu)(hu)程(cheng)序,將編輯好的(de)(de)電(dian)(dian)子郵(you)(you)件(jian)(jian)向郵(you)(you)局服(fu)(fu)務(wu)(wu)(wu)(wu)器(qi)(qi)(qi)(SMTP服(fu)(fu)務(wu)(wu)(wu)(wu)器(qi)(qi)(qi))發送(song)。郵(you)(you)局服(fu)(fu)務(wu)(wu)(wu)(wu)器(qi)(qi)(qi)識別接(jie)(jie)收(shou)(shou)(shou)者(zhe)的(de)(de)地址,并向管(guan)理該(gai)地址的(de)(de)郵(you)(you)件(jian)(jian)服(fu)(fu)務(wu)(wu)(wu)(wu)器(qi)(qi)(qi)(POP3服(fu)(fu)務(wu)(wu)(wu)(wu)器(qi)(qi)(qi))發送(song)消息。郵(you)(you)件(jian)(jian)服(fu)(fu)務(wu)(wu)(wu)(wu)器(qi)(qi)(qi)識將消息存放在接(jie)(jie)收(shou)(shou)(shou)者(zhe)的(de)(de)電(dian)(dian)子信箱內(nei),并告知(zhi)接(jie)(jie)收(shou)(shou)(shou)者(zhe)有(you)新(xin)郵(you)(you)件(jian)(jian)到(dao)(dao)來(lai)。接(jie)(jie)收(shou)(shou)(shou)者(zhe)通(tong)過(guo)郵(you)(you)件(jian)(jian)客(ke)戶(hu)(hu)程(cheng)序連接(jie)(jie)到(dao)(dao)服(fu)(fu)務(wu)(wu)(wu)(wu)器(qi)(qi)(qi)后,就會看到(dao)(dao)服(fu)(fu)務(wu)(wu)(wu)(wu)器(qi)(qi)(qi)的(de)(de)通(tong)知(zhi),進而(er)打開自己的(de)(de)電(dian)(dian)子信箱來(lai)查收(shou)(shou)(shou)郵(you)(you)件(jian)(jian)。
通常Internet上的(de)(de)(de)個(ge)(ge)人用(yong)(yong)戶(hu)不能直接(jie)接(jie)收(shou)(shou)電(dian)(dian)子(zi)(zi)郵(you)(you)(you)(you)件(jian)(jian),而是通過申請ISP主(zhu)機(ji)的(de)(de)(de)一(yi)個(ge)(ge)電(dian)(dian)子(zi)(zi)信(xin)箱,由(you)ISP主(zhu)機(ji)負責電(dian)(dian)子(zi)(zi)郵(you)(you)(you)(you)件(jian)(jian)的(de)(de)(de)接(jie)收(shou)(shou)。一(yi)旦有用(yong)(yong)戶(hu)的(de)(de)(de)電(dian)(dian)子(zi)(zi)郵(you)(you)(you)(you)件(jian)(jian)到(dao)來(lai),ISP主(zhu)機(ji)就將郵(you)(you)(you)(you)件(jian)(jian)移到(dao)用(yong)(yong)戶(hu)的(de)(de)(de)電(dian)(dian)子(zi)(zi)信(xin)箱內,并(bing)通知(zhi)用(yong)(yong)戶(hu)有新郵(you)(you)(you)(you)件(jian)(jian)。因此(ci),當發送一(yi)條(tiao)電(dian)(dian)子(zi)(zi)郵(you)(you)(you)(you)件(jian)(jian)給一(yi)另(ling)一(yi)個(ge)(ge)客戶(hu)時,電(dian)(dian)子(zi)(zi)郵(you)(you)(you)(you)件(jian)(jian)首先從(cong)用(yong)(yong)戶(hu)計算機(ji)發送到(dao)ISP主(zhu)機(ji),再到(dao)Internet,再到(dao)收(shou)(shou)件(jian)(jian)人的(de)(de)(de)ISP主(zhu)機(ji),最后到(dao)收(shou)(shou)件(jian)(jian)人的(de)(de)(de)個(ge)(ge)人計算機(ji)。
ISP主機起著“郵局”的作用,管理著眾多用戶的電子信箱。每個用(yong)戶的(de)電(dian)(dian)子(zi)信箱(xiang)實(shi)際上就是(shi)用(yong)戶所申請(qing)的(de)帳號名。每個用(yong)戶的(de)電(dian)(dian)子(zi)郵(you)件(jian)信箱(xiang)都要占用(yong)ISP主(zhu)機一定(ding)容(rong)量的(de)硬盤空(kong)(kong)間,由(you)于這(zhe)一空(kong)(kong)間是(shi)有限的(de),因(yin)此用(yong)戶要定(ding)期查收和閱讀電(dian)(dian)子(zi)信箱(xiang)中的(de)郵(you)件(jian),以(yi)便(bian)騰出空(kong)(kong)間來接收新的(de)郵(you)件(jian)。