Lani's Study Books

Gmail fans often cite great spam protection as a key reason they love Gmail. It's relatively easy to catch spam messages; the challenge is to catch the right messages without blocking mail you want along the way.

How do we do it? Our team of leading spam-fighting scientists uses a number of advanced Google technologies. Though in many cases our best weapon is you.

Community clicks

Gmail users play an important role in keeping spammy messages out of millions of inboxes. When the Gmail community votes with their clicks to report a particular email as spam, our system quickly learns to start blocking similar messages. The more spam the community marks, the smarter our system becomes.

Quick adaptation

The same advanced computing infrastructure that powers Google search also tunes our spam filters. As new spam data is released, the scale of Google's computer network allows us to quickly modify Gmail's spam-fighting algorithms. It's often a matter of minutes between the time a spammer sends out a new type of junk mail and when it's blocked from Gmail accounts.

Powered by Google

Many Google teams provide pieces of the spam-protection puzzle, from distributed computing to language detection. For example, we use optical character recognition (OCR) developed by the Google Book Search team to protect Gmail users from image spam. And machine-learning algorithms developed to merge and rank large sets of Google search results allow us to combine hundreds of factors to classify spam.

Authentication, for everyone

Many webmail services support a single authentication system to verify senders and help identify forged messages. Gmail supports multiple authentication systems, including SPF (Sender Policy Framework), DomainKeys, and DKIM (DomainKeys Identified Mail), so we can be more certain that your mail is from who it says it's from. Also, unlike many other providers that automatically let through all mail from certain senders, making it possible for their messages to bypass spam filters, Gmail puts all senders through the same rigorous checks.

Data from：http://www.google.com/mail/help/fightspam/spamexplained.html

39.25 Data returned by DNS lists

DNS lists are constructed using address records in the DNS. The original RBL just used the address 127.0.0.1 on the right hand side of each record, but the RBL+ list and some other lists use a number of values with different meanings. The values used on the RBL+ list are:

127.1.0.1 RBL
127.1.0.2 DUL
127.1.0.3 DUL and RBL
127.1.0.4 RSS
127.1.0.5 RSS and RBL
127.1.0.6 RSS and DUL
127.1.0.7 RSS and DUL and RBL

Some DNS lists may return more than one address record.

http://www.exim.org/exim-html-4.50/doc/html/spec.html

旅行可增廣見聞，不過各國民俗風情不同，一個不小心，諸如用錯手勢或表錯情，輕則被對方會錯意，重則犯了當地禁忌，成為不受歡迎人物，敗了遊興。

1、在伊朗切勿豎起大拇指

若想稱讚對方表現不俗，許多人會豎起大拇指，不過在伊朗，這可是猥褻手勢，意味「坐在這上面」，極為不雅。此外，OK手勢是許多潛水族通用的暗號，表示「我很好」，不過在土耳其與巴西，OK手勢是罵人之意，表示對方下流齷齪。所以下次到巴西潛水時，千萬別隨便OK。

2、切勿觸摸泰國人的頭

在信奉佛教的泰國，頭則是靈魂之所，不可隨便亂摸。此外，也不可用手指指東指西。

3、視國情而挑話題與當地人談論

有時無知也令當地人感冒。諸如，在澳洲詢問原住民的處境，在中國暢談人權，在印度追究女性何以死於嫁妝不足，在西班牙譴責鬥牛等。最好選些安全的話題，諸如食物、小孩、運動、美容與景點等，多說好話包準不會錯。

4、切忌換上牛仔服或印第安傳統服飾出席阿根廷烤肉會

許多人到了海外，難免想入境隨俗，試試當地的服飾，因此到了夏威夷，換上五彩繽紛的夏威夷衫，到了印尼，穿上蠟染的服飾。不過在阿根廷，歐洲人若換上牛仔服或印第安傳統服飾盛裝出席烤肉會，只會被當地人嘲弄，認為他們小題大做。

5、不能穿鞋子進家與入廟

在日本等東方國家，進入室內或廟宇前，一定得脫鞋。稍早英國女星伊莉莎白·赫莉在印度舉行婚禮，因為進入結婚殿堂時拒絕脫鞋，差點把自己婚禮搞砸。

6、送什麼花也有禁忌

受邀到別人家作客，可以送女主人一束鮮花，不過在德國、波蘭、瑞典，千萬別送康乃馨。在比利時、義大利、法國、西班牙、土耳其等國，菊花則是禁忌。因為康乃馨與菊花都是喪禮用花。而玫瑰代表的意義也因國而異。在法國、奧地利，紅玫瑰代表浪漫，不過黃玫瑰在墨西哥與智利，代表離別。此外，花朵數目、包裝與否，都會影響送禮情意，不可不慎。

7、送瓶裝在豬皮製瓶套的白蘭地給阿拉伯主人

這可是大不敬。穆斯林如果喝酒，一定不會公開喝，不管你的東道主愛喝白蘭地或威士忌，讓他喝酒時引人注意絕非好事。豬和狗在阿拉伯國家都是不潔淨的動物，因此不管你送他的酒瓶皮套有多華麗，只要是豬皮製，都是在侮辱主人。送禮是門學問，因此送禮前最好問問當地人意見。在中國，送鐘可是觸人楣頭。在哥倫比亞，禮品最好不要有標記，以免被視為便宜貨。韓國人則喜歡洋貨。

8、在喬治亞或亞塞拜然，舉杯頌祝健康時，切忌自顧飲酒或與人交談。

北歐、俄羅斯、前蘇聯加盟共和國，對於敬酒非常慎重，舉杯時最好眼睛看著主人。在俄國，敬完酒後須一口將杯中的伏特加飲盡。在喬治亞和亞塞拜然，有專人主持敬酒，整個過程往往耗上數個小時。敬酒時，如果和身旁的人交談或逕自獨酌，將會遭致責難或白眼。

9、在中國與日本，切忌將筷子插於米飯上

在中國與日本，用筷也有一套禮儀：千萬別將筷子直直插入碗裡，也不可用筷子指人。

筷子要握在上方三分之二處，握筷子處愈遠離食物，人們愈會覺得你世故老練。千萬不要把筷子當叉子用，也不要把筷子架成十字形、分開來擺在餐具兩邊，將尖端指向別人。最糟糕的莫過於將筷子插在米飯上，這樣做會讓人聯想到喪禮儀式。

引用來源