多年来，我慢慢地开发了一个正则表达式，它可以正确验证大多数电子邮件地址，假设它们不使用IP地址作为服务器部分。
我在几个PHP程序中使用它，而且大多数时候都可以使用。然而，不时有人与我联系，他们对使用它的网站有问题，我最终不得不做出一些调整（最近我意识到我不允许四个字符的TLD）。
你有或见过验证电子邮件的最佳正则表达式是什么？
我见过几种使用函数的解决方案，这些函数使用了几个较短的表达式，但我宁愿在简单函数中使用一个长的复杂表达式，而不是在更复杂的函数中使用几个短表达式。
当前回答
这个正则表达式来自Perl的Email:：Valid库。我相信它是最准确的，它符合所有RFC 822。而且，它基于O'Reilly书中的正则表达式：
使用Jeffrey Friedl的示例构建的正则表达式掌握正则表达式(http://www.ora.com/catalog/regexp/).
$RFC822PAT = <<'EOF';
[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\
xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xf
f\n\015()]*)*\)[\040\t]*)*(?:(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\x
ff]+(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff])|"[^\\\x80-\xff\n\015
"]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015"]*)*")[\040\t]*(?:\([^\\\x80-\
xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80
-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*
)*(?:\.[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\
\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\
x80-\xff\n\015()]*)*\)[\040\t]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x8
0-\xff]+(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff])|"[^\\\x80-\xff\n
\015"]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015"]*)*")[\040\t]*(?:\([^\\\x
80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^
\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040
\t]*)*)*@[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([
^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\
\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\
x80-\xff]+(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff])|\[(?:[^\\\x80-
\xff\n\015\[\]]|\\[^\x80-\xff])*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()
]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\
x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:\.[\04
0\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\
n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\
015()]*)*\)[\040\t]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?!
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff])|\[(?:[^\\\x80-\xff\n\015\[\
]]|\\[^\x80-\xff])*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\
x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\01
5()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*)*|(?:[^(\040)<>@,;:".
\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]
)|"[^\\\x80-\xff\n\015"]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015"]*)*")[^
()<>@,;:".\\\[\]\x80-\xff\000-\010\012-\037]*(?:(?:\([^\\\x80-\xff\n\0
15()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][
^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)|"[^\\\x80-\xff\
n\015"]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015"]*)*")[^()<>@,;:".\\\[\]\
x80-\xff\000-\010\012-\037]*)*<[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?
:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-
\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:@[\040\t]*
(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015
()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()
]*)*\)[\040\t]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\0
40)<>@,;:".\\\[\]\000-\037\x80-\xff])|\[(?:[^\\\x80-\xff\n\015\[\]]|\\
[^\x80-\xff])*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\
xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*
)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:\.[\040\t]*(?:\([^\\\x80
-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x
80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t
]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".\\
\[\]\000-\037\x80-\xff])|\[(?:[^\\\x80-\xff\n\015\[\]]|\\[^\x80-\xff])
*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x
80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80
-\xff\n\015()]*)*\)[\040\t]*)*)*(?:,[\040\t]*(?:\([^\\\x80-\xff\n\015(
)]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\
\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*@[\040\t
]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\0
15()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015
()]*)*\)[\040\t]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(
\040)<>@,;:".\\\[\]\000-\037\x80-\xff])|\[(?:[^\\\x80-\xff\n\015\[\]]|
\\[^\x80-\xff])*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80
-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()
]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:\.[\040\t]*(?:\([^\\\x
80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^
\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040
\t]*)*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".
\\\[\]\000-\037\x80-\xff])|\[(?:[^\\\x80-\xff\n\015\[\]]|\\[^\x80-\xff
])*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\
\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x
80-\xff\n\015()]*)*\)[\040\t]*)*)*)*:[\040\t]*(?:\([^\\\x80-\xff\n\015
()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\
\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*)?(?:[^
(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".\\\[\]\000-
\037\x80-\xff])|"[^\\\x80-\xff\n\015"]*(?:\\[^\x80-\xff][^\\\x80-\xff\
n\015"]*)*")[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|
\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))
[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:\.[\040\t]*(?:\([^\\\x80-\xff
\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\x
ff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(
?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".\\\[\]\
000-\037\x80-\xff])|"[^\\\x80-\xff\n\015"]*(?:\\[^\x80-\xff][^\\\x80-\
xff\n\015"]*)*")[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\x
ff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)
*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*)*@[\040\t]*(?:\([^\\\x80-\x
ff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-
\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)
*(?:[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".\\\[\
]\000-\037\x80-\xff])|\[(?:[^\\\x80-\xff\n\015\[\]]|\\[^\x80-\xff])*\]
)[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-
\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\x
ff\n\015()]*)*\)[\040\t]*)*(?:\.[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(
?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80
-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:[^(\040)<
>@,;:".\\\[\]\000-\037\x80-\xff]+(?![^(\040)<>@,;:".\\\[\]\000-\037\x8
0-\xff])|\[(?:[^\\\x80-\xff\n\015\[\]]|\\[^\x80-\xff])*\])[\040\t]*(?:
\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]
*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)
*\)[\040\t]*)*)*>)
EOF
其他回答
我没有发现任何涉及顶级域名的，但应该考虑。
所以对我来说，以下方法奏效了：
[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+(?:[A-Z]{2}AAA|AARP|ABB|ABBOTT|ABOGADO|AC|ACADEMY|ACCENTURE|ACCOUNTANT|ACCOUNTANTS|ACO|ACTIVE|ACTOR|AD|ADAC|ADS|ADULT|AE|AEG|AERO|AF|AFL|AG|AGENCY|AI|AIG|AIRFORCE|AIRTEL|AL|ALIBABA|ALIPAY|ALLFINANZ|ALSACE|AM|AMICA|AMSTERDAM|ANALYTICS|ANDROID|AO|APARTMENTS|APP|APPLE|AQ|AQUARELLE|AR|ARAMCO|ARCHI|ARMY|ARPA|ARTE|AS|ASIA|ASSOCIATES|AT|ATTORNEY|AU|AUCTION|AUDI|AUDIO|AUTHOR|AUTO|AUTOS|AW|AX|AXA|AZ|AZURE|BA|BAIDU|BAND|BANK|BAR|BARCELONA|BARCLAYCARD|BARCLAYS|BARGAINS|BAUHAUS|BAYERN|BB|BBC|BBVA|BCN|BD|BE|BEATS|BEER|BENTLEY|BERLIN|BEST|BET|BF|BG|BH|BHARTI|BI|BIBLE|BID|BIKE|BING|BINGO|BIO|BIZ|BJ|BLACK|BLACKFRIDAY|BLOOMBERG|BLUE|BM|BMS|BMW|BN|BNL|BNPPARIBAS|BO|BOATS|BOEHRINGER|BOM|BOND|BOO|BOOK|BOOTS|BOSCH|BOSTIK|BOT|BOUTIQUE|BR|BRADESCO|BRIDGESTONE|BROADWAY|BROKER|BROTHER|BRUSSELS|BS|BT|BUDAPEST|BUGATTI|BUILD|BUILDERS|BUSINESS|BUY|BUZZ|BV|BW|BY|BZ|BZH|CA|CAB|CAFE|CAL|CALL|CAMERA|CAMP|CANCERRESEARCH|CANON|CAPETOWN|CAPITAL|CAR|CARAVAN|CARDS|CARE|CAREER|CAREERS|CARS|CARTIER|CASA|CASH|CASINO|CAT|CATERING|CBA|CBN|CC|CD|CEB|CENTER|CEO|CERN|CF|CFA|CFD|CG|CH|CHANEL|CHANNEL|CHAT|CHEAP|CHLOE|CHRISTMAS|CHROME|CHURCH|CI|CIPRIANI|CIRCLE|CISCO|CITIC|CITY|CITYEATS|CK|CL|CLAIMS|CLEANING|CLICK|CLINIC|CLINIQUE|CLOTHING|CLOUD|CLUB|CLUBMED|CM|CN|CO|COACH|CODES|COFFEE|COLLEGE|COLOGNE|COM|COMMBANK|COMMUNITY|COMPANY|COMPARE|COMPUTER|COMSEC|CONDOS|CONSTRUCTION|CONSULTING|CONTACT|CONTRACTORS|COOKING|COOL|COOP|CORSICA|COUNTRY|COUPONS|COURSES|CR|CREDIT|CREDITCARD|CREDITUNION|CRICKET|CROWN|CRS|CRUISES|CSC|CU|CUISINELLA|CV|CW|CX|CY|CYMRU|CYOU|CZ|DABUR|DAD|DANCE|DATE|DATING|DATSUN|DAY|DCLK|DE|DEALER|DEALS|DEGREE|DELIVERY|DELL|DELTA|DEMOCRAT|DENTAL|DENTIST|DESI|DESIGN|DEV|DIAMONDS|DIET|DIGITAL|DIRECT|DIRECTORY|DISCOUNT|DJ|DK|DM|DNP|DO|DOCS|DOG|DOHA|DOMAINS|DOOSAN|DOWNLOAD|DRIVE|DUBAI|DURBAN|DVAG|DZ|EARTH|EAT|EC|EDEKA|EDU|EDUCATION|EE|EG|EMAIL|EMERCK|ENERGY|ENGINEER|ENGINEERING|ENTERPRISES|EPSON|EQUIPMENT|ER|ERNI|ES|ESQ|ESTATE|ET|EU|EUROVISION|EUS|EVENTS|EVERBANK|EXCHANGE|EXPERT|EXPOSED|EXPRESS|FAGE|FAIL|FAIRWINDS|FAITH|FAMILY|FAN|FANS|FARM|FASHION|FAST|FEEDBACK|FERRERO|FI|FILM|FINAL|FINANCE|FINANCIAL|FIRESTONE|FIRMDALE|FISH|FISHING|FIT|FITNESS|FJ|FK|FLIGHTS|FLORIST|FLOWERS|FLSMIDTH|FLY|FM|FO|FOO|FOOTBALL|FORD|FOREX|FORSALE|FORUM|FOUNDATION|FOX|FR|FRESENIUS|FRL|FROGANS|FUND|FURNITURE|FUTBOL|FYI|GA|GAL|GALLERY|GAME|GARDEN|GB|GBIZ|GD|GDN|GE|GEA|GENT|GENTING|GF|GG|GGEE|GH|GI|GIFT|GIFTS|GIVES|GIVING|GL|GLASS|GLE|GLOBAL|GLOBO|GM|GMAIL|GMO|GMX|GN|GOLD|GOLDPOINT|GOLF|GOO|GOOG|GOOGLE|GOP|GOT|GOV|GP|GQ|GR|GRAINGER|GRAPHICS|GRATIS|GREEN|GRIPE|GROUP|GS|GT|GU|GUCCI|GUGE|GUIDE|GUITARS|GURU|GW|GY|HAMBURG|HANGOUT|HAUS|HEALTH|HEALTHCARE|HELP|HELSINKI|HERE|HERMES|HIPHOP|HITACHI|HIV|HK|HM|HN|HOCKEY|HOLDINGS|HOLIDAY|HOMEDEPOT|HOMES|HONDA|HORSE|HOST|HOSTING|HOTELES|HOTMAIL|HOUSE|HOW|HR|HSBC|HT|HU|HYUNDAI|IBM|ICBC|ICE|ICU|ID|IE|IFM|IINET|IL|IM|IMMO|IMMOBILIEN|IN|INDUSTRIES|INFINITI|INFO|ING|INK|INSTITUTE|INSURANCE|INSURE|INT|INTERNATIONAL|INVESTMENTS|IO|IPIRANGA|IQ|IR|IRISH|IS|ISELECT|IST|ISTANBUL|IT|ITAU|IWC|JAGUAR|JAVA|JCB|JE|JETZT|JEWELRY|JLC|JLL|JM|JMP|JO|JOBS|JOBURG|JOT|JOY|JP|JPRS|JUEGOS|KAUFEN|KDDI|KE|KFH|KG|KH|KI|KIA|KIM|KINDER|KITCHEN|KIWI|KM|KN|KOELN|KOMATSU|KP|KPN|KR|KRD|KRED|KW|KY|KYOTO|KZ|LA|LACAIXA|LAMBORGHINI|LAMER|LANCASTER|LAND|LANDROVER|LANXESS|LASALLE|LAT|LATROBE|LAW|LAWYER|LB|LC|LDS|LEASE|LECLERC|LEGAL|LEXUS|LGBT|LI|LIAISON|LIDL|LIFE|LIFEINSURANCE|LIFESTYLE|LIGHTING|LIKE|LIMITED|LIMO|LINCOLN|LINDE|LINK|LIVE|LIVING|LIXIL|LK|LOAN|LOANS|LOL|LONDON|LOTTE|LOTTO|LOVE|LR|LS|LT|LTD|LTDA|LU|LUPIN|LUXE|LUXURY|LV|LY|MA|MADRID|MAIF|MAISON|MAKEUP|MAN|MANAGEMENT|MANGO|MARKET|MARKETING|MARKETS|MARRIOTT|MBA|MC|MD|ME|MED|MEDIA|MEET|MELBOURNE|MEME|MEMORIAL|MEN|MENU|MEO|MG|MH|MIAMI|MICROSOFT|MIL|MINI|MK|ML|MM|MMA|MN|MO|MOBI|MOBILY|MODA|MOE|MOI|MOM|MONASH|MONEY|MONTBLANC|MORMON|MORTGAGE|MOSCOW|MOTORCYCLES|MOV|MOVIE|MOVISTAR|MP|MQ|MR|MS|MT|MTN|MTPC|MTR|MU|MUSEUM|MUTUELLE|MV|MW|MX|MY|MZ|NA|NADEX|NAGOYA|NAME|NAVY|NC|NE|NEC|NET|NETBANK|NETWORK|NEUSTAR|NEW|NEWS|NEXUS|NF|NG|NGO|NHK|NI|NICO|NINJA|NISSAN|NL|NO|NOKIA|NORTON|NOWRUZ|NP|NR|NRA|NRW|NTT|NU|NYC|NZ|OBI|OFFICE|OKINAWA|OM|OMEGA|ONE|ONG|ONL|ONLINE|OOO|ORACLE|ORANGE|ORG|ORGANIC|ORIGINS|OSAKA|OTSUKA|OVH|PA|PAGE|PAMPEREDCHEF|PANERAI|PARIS|PARS|PARTNERS|PARTS|PARTY|PE|PET|PF|PG|PH|PHARMACY|PHILIPS|PHOTO|PHOTOGRAPHY|PHOTOS|PHYSIO|PIAGET|PICS|PICTET|PICTURES|PID|PIN|PING|PINK|PIZZA|PK|PL|PLACE|PLAY|PLAYSTATION|PLUMBING|PLUS|PM|PN|POHL|POKER|PORN|POST|PR|PRAXI|PRESS|PRO|PROD|PRODUCTIONS|PROF|PROMO|PROPERTIES|PROPERTY|PROTECTION|PS|PT|PUB|PW|PY|QA|QPON|QUEBEC|RACING|RE|READ|REALTOR|REALTY|RECIPES|RED|REDSTONE|REDUMBRELLA|REHAB|REISE|REISEN|REIT|REN|RENT|RENTALS|REPAIR|REPORT|REPUBLICAN|REST|RESTAURANT|REVIEW|REVIEWS|REXROTH|RICH|RICOH|RIO|RIP|RO|ROCHER|ROCKS|RODEO|ROOM|RS|RSVP|RU|RUHR|RUN|RW|RWE|RYUKYU|SA|SAARLAND|SAFE|SAFETY|SAKURA|SALE|SALON|SAMSUNG|SANDVIK|SANDVIKCOROMANT|SANOFI|SAP|SAPO|SARL|SAS|SAXO|SB|SBS|SC|SCA|SCB|SCHAEFFLER|SCHMIDT|SCHOLARSHIPS|SCHOOL|SCHULE|SCHWARZ|SCIENCE|SCOR|SCOT|SD|SE|SEAT|SECURITY|SEEK|SELECT|SENER|SERVICES|SEVEN|SEW|SEX|SEXY|SFR|SG|SH|SHARP|SHELL|SHIA|SHIKSHA|SHOES|SHOW|SHRIRAM|SI|SINGLES|SITE|SJ|SK|SKI|SKIN|SKY|SKYPE|SL|SM|SMILE|SN|SNCF|SO|SOCCER|SOCIAL|SOFTBANK|SOFTWARE|SOHU|SOLAR|SOLUTIONS|SONY|SOY|SPACE|SPIEGEL|SPREADBETTING|SR|SRL|ST|STADA|STAR|STARHUB|STATEFARM|STATOIL|STC|STCGROUP|STOCKHOLM|STORAGE|STUDIO|STUDY|STYLE|SU|SUCKS|SUPPLIES|SUPPLY|SUPPORT|SURF|SURGERY|SUZUKI|SV|SWATCH|SWISS|SX|SY|SYDNEY|SYMANTEC|SYSTEMS|SZ|TAB|TAIPEI|TAOBAO|TATAMOTORS|TATAR|TATTOO|TAX|TAXI|TC|TCI|TD|TEAM|TECH|TECHNOLOGY|TEL|TELEFONICA|TEMASEK|TENNIS|TF|TG|TH|THD|THEATER|THEATRE|TICKETS|TIENDA|TIFFANY|TIPS|TIRES|TIROL|TJ|TK|TL|TM|TMALL|TN|TO|TODAY|TOKYO|TOOLS|TOP|TORAY|TOSHIBA|TOURS|TOWN|TOYOTA|TOYS|TR|TRADE|TRADING|TRAINING|TRAVEL|TRAVELERS|TRAVELERSINSURANCE|TRUST|TRV|TT|TUBE|TUI|TUSHU|TV|TW|TZ|UA|UBS|UG|UK|UNIVERSITY|UNO|UOL|US|UY|UZ|VA|VACATIONS|VANA|VC|VE|VEGAS|VENTURES|VERISIGN|VERSICHERUNG|VET|VG|VI|VIAJES|VIDEO|VILLAS|VIN|VIP|VIRGIN|VISION|VISTA|VISTAPRINT|VIVA|VLAANDEREN|VN|VODKA|VOLKSWAGEN|VOTE|VOTING|VOTO|VOYAGE|VU|WALES|WALTER|WANG|WANGGOU|WATCH|WATCHES|WEATHER|WEBCAM|WEBER|WEBSITE|WED|WEDDING|WEIR|WF|WHOSWHO|WIEN|WIKI|WILLIAMHILL|WIN|WINDOWS|WINE|WME|WORK|WORKS|WORLD|WS|WTC|WTF|XBOX|XEROX|XIN|XN--11B4C3D|XN--1QQW23A|XN--30RR7Y|XN--3BST00M|XN--3DS443G|XN--3E0B707E|XN--3PXU8K|XN--42C2D9A|XN--45BRJ9C|XN--45Q11C|XN--4GBRIM|XN--55QW42G|XN--55QX5D|XN--6FRZ82G|XN--6QQ986B3XL|XN--80ADXHKS|XN--80AO21A|XN--80ASEHDB|XN--80ASWG|XN--90A3AC|XN--90AIS|XN--9DBQ2A|XN--9ET52U|XN--B4W605FERD|XN--C1AVG|XN--C2BR7G|XN--CG4BKI|XN--CLCHC0EA0B2G2A9GCD|XN--CZR694B|XN--CZRS0T|XN--CZRU2D|XN--D1ACJ3B|XN--D1ALF|XN--ECKVDTC9D|XN--EFVY88H|XN--ESTV75G|XN--FHBEI|XN--FIQ228C5HS|XN--FIQ64B|XN--FIQS8S|XN--FIQZ9S|XN--FJQ720A|XN--FLW351E|XN--FPCRJ9C3D|XN--FZC2C9E2C|XN--G2XX48C|XN--GECRJ9C|XN--H2BRJ9C|XN--HXT814E|XN--I1B6B1A6A2E|XN--IMR513N|XN--IO0A7I|XN--J1AEF|XN--J1AMH|XN--J6W193G|XN--JLQ61U9W7B|XN--KCRX77D1X4A|XN--KPRW13D|XN--KPRY57D|XN--KPU716F|XN--KPUT3I|XN--L1ACC|XN--LGBBAT1AD8J|XN--MGB9AWBF|XN--MGBA3A3EJT|XN--MGBA3A4F16A|XN--MGBAAM7A8H|XN--MGBAB2BD|XN--MGBAYH7GPA|XN--MGBB9FBPOB|XN--MGBBH1A71E|XN--MGBC0A9AZCG|XN--MGBERP4A5D4AR|XN--MGBPL2FH|XN--MGBT3DHD|XN--MGBTX2B|XN--MGBX4CD0AB|XN--MK1BU44C|XN--MXTQ1M|XN--NGBC5AZD|XN--NGBE9E0A|XN--NODE|XN--NQV7F|XN--NQV7FS00EMA|XN--NYQY26A|XN--O3CW4H|XN--OGBPF8FL|XN--P1ACF|XN--P1AI|XN--PBT977C|XN--PGBS0DH|XN--PSSY2U|XN--Q9JYB4C|XN--QCKA1PMC|XN--QXAM|XN--RHQV96G|XN--S9BRJ9C|XN--SES554G|XN--T60B56A|XN--TCKWE|XN--UNUP4Y|XN--VERMGENSBERATER-CTB|XN--VERMGENSBERATUNG-PWB|XN--VHQUV|XN--VUQ861B|XN--WGBH1C|XN--WGBL6A|XN--XHQ521B|XN--XKC2AL3HYE2A|XN--XKC2DL3A5EE0H|XN--Y9A3AQ|XN--YFRO4I67O|XN--YGBI2AMMX|XN--ZFR164B|XPERIA|XXX|XYZ|YACHTS|YAMAXUN|YANDEX|YE|YODOBASHI|YOGA|YOKOHAMA|YOUTUBE|YT|ZA|ZARA|ZERO|ZIP|ZM|ZONE|ZUERICH|ZW)\b
容易丢弃的电子邮件3c296rD3HNEE@d139c.a51, Sd@sd.dox等
如果需要，可以进一步编辑域名，例如特定国家域等。
另一个经常更新的顶级域列表。
您不应使用正则表达式来验证电子邮件地址。
相反，在C#中使用MailAddress类，如下所示：
try {
address = new MailAddress(address).Address;
} catch(FormatException) {
// address is invalid
}
MailAddress类使用BNF解析器完全按照RFC822验证地址。
如果您计划使用MailAddress验证电子邮件地址，请注意，此方法也接受电子邮件地址的显示名称部分，这可能不是您想要实现的。例如，它接受这些字符串作为有效的电子邮件地址：
"user1@hotmail.com; user2@gmail.com""user1@hotmail.com; user2@gmail.com; user3@company.com"“”用户显示名称“user3@company.com"“user4@company.com”
在某些情况下，只有字符串的最后一部分被解析为地址；之前的其余部分是显示名称。要获得没有任何显示名称的普通电子邮件地址，可以对照原始字符串检查规范化地址。
bool isValid = false;
try
{
MailAddress address = new MailAddress(emailAddress);
isValid = (address.Address == emailAddress);
// or
// isValid = string.IsNullOrEmpty(address.DisplayName);
}
catch (FormatException)
{
// address is invalid
}
此外，在末尾有一个点的地址，如user@company.邮件地址也接受。
如果你真的想使用正则表达式，这里是：
(?:(?:\r\n)?[ \t])*(?:(?:(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t] )+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?: \r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:( ?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*))*@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\0 31]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\ ](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+ (?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?: (?:\r\n)?[ \t])*))*|(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z |(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n) ?[ \t])*)*\<(?:(?:\r\n)?[ \t])*(?:@(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\ r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n) ?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t] )*))*(?:,@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])* )(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t] )+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*) *:(?:(?:\r\n)?[ \t])*)?(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+ |\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r \n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?: \r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t ]))*"(?:(?:\r\n)?[ \t])*))*@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031 ]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\]( ?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(? :(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(? :\r\n)?[ \t])*))*\>(?:(?:\r\n)?[ \t])*)|(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(? :(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)? [ \t]))*"(?:(?:\r\n)?[ \t])*)*:(?:(?:\r\n)?[ \t])*(?:(?:(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]| \\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<> @,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|" (?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*))*@(?:(?:\r\n)?[ \t] )*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\ ".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(? :[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[ \]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*|(?:[^()<>@,;:\\".\[\] \000- \031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|( ?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)*\<(?:(?:\r\n)?[ \t])*(?:@(?:[^()<>@,; :\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([ ^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\" .\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\ ]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*(?:,@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\ [\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\ r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\] |\\.)*\](?:(?:\r\n)?[ \t])*))*)*:(?:(?:\r\n)?[ \t])*)?(?:[^()<>@,;:\\".\[\] \0 00-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\ .|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@, ;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(? :[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*))*@(?:(?:\r\n)?[ \t])* (?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\". \[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[ ^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\] ]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*\>(?:(?:\r\n)?[ \t])*)(?:,\s*( ?:(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\ ".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)(?:\.(?:( ?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[ \["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t ])*))*@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t ])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(? :\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+| \Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*|(?: [^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\ ]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)*\<(?:(?:\r\n) ?[ \t])*(?:@(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\[" ()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n) ?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<> @,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*(?:,@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@, ;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t] )*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\ ".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*)*:(?:(?:\r\n)?[ \t])*)? (?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\". \[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)(?:\.(?:(?: \r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\[ "()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t]) *))*@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t]) +|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\ .(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z |(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*\>(?:( ?:\r\n)?[ \t])*))*)?;\s*)
完全符合RFC 822的正则表达式由于其长度而效率低下且晦涩难懂。幸运的是，RFC 822被两次取代，当前的电子邮件地址规范是RFC 5322。RFC 5322产生了一个正则表达式，如果研究几分钟就可以理解，并且对于实际使用来说足够有效。
一个符合RFC 5322的正则表达式可以在页面顶部找到：http://emailregex.com/但使用的IP地址模式在互联网上浮动，错误是允许点分隔地址中的任何无符号字节十进制值为00，这是非法的。它的其余部分似乎与RFC 5322语法一致，并通过了几个使用grep-Po的测试，包括域名、IP地址、坏域名以及带引号和不带引号的帐户名。
纠正了IP模式中的00错误，我们获得了一个有效且相当快的正则表达式。（抓取呈现的版本，而不是markdown，以获取实际代码。）
（？：[a-z0-9！#$%&'*+/=？^_`{|}~-]+（？：\.[a-z0-9！#$%&'*+/=？^ _`{|}~-]+）*|“（？：[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-#x09\x0b#x0c\x10e-\x7f]）*”）@（？：（？：[？：[a-z0-9]（？：a-z0-9-]*[a-z0-9]）？\.）+[a-z0-9]（？：[a-z0-9-]*[a-z0-9]）|\[(?:(?:(2(5[0-5]|[0-4][0-9])|1[0-9][0-9]|[1-9]?[0-9]))\.){3}(?:(2(5[0-5]|[0-4][0-9])|1[0-9][0-9]|[1-9]?[0-9]）|[a-z0-9-]*[a-z0-9]：（？：[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-#x09\x0b#x0c\x10e-\x7f】）+）\]）
or:
(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:(2(5[0-5]|[0-4][0-9])|1[0-9][0-9]|[1-9]?[0-9]))\.){3}(?:(2(5[0-5]|[0-4][0-9])|1[0-9][0-9]|[1-9]?[0-9])|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])
下面是上述正则表达式的有限状态机图，它比正则表达式本身更清楚
Perl和PCRE中更复杂的模式（例如PHP中使用的正则表达式库）可以正确地解析RFC 5322而不会出现问题。Python和C#也可以做到这一点，但它们使用的语法与前两种不同。然而，如果您被迫使用许多功能较弱的模式匹配语言之一，那么最好使用真正的解析器。
同样重要的是要理解，根据RFC验证它绝对不会告诉您该地址是否确实存在于所提供的域中，或者输入该地址的人是否是其真正的所有者。人们总是以这种方式向其他人注册邮件列表。修复这一问题需要一种更高级的验证，包括向该地址发送一条消息，该消息包含一个确认令牌，该令牌与该地址在同一网页上输入。
确认令牌是知道您获得输入者地址的唯一方法。这就是为什么现在大多数邮件列表都使用该机制来确认注册。毕竟，任何人都可以放下president@whitehouse.gov，这甚至会被解析为合法，但不太可能是另一端的人。
对于PHP，您不应该使用“用PHP验证电子邮件地址”中给出的模式，我引用的正确方法是：
常见的用法和广泛的草率编码可能会为电子邮件地址建立一个事实上的标准，这比记录的正式标准更具限制性。
这并不比其他所有非RFC模式更好。它甚至不足以处理RFC 822，更不用说RFC 5322了。然而，这一个是。
如果你想变得花哨和迂腐，就实现一个完整的状态引擎。正则表达式只能充当基本过滤器。正则表达式的问题是，从用户的角度来看，告诉某人他们完全有效的电子邮件地址是无效的（假阳性），因为你的正则表达式无法处理它，这是粗鲁和不礼貌的。用于此目的的状态引擎可以验证甚至纠正电子邮件地址，否则这些地址将被视为无效，因为它根据每个RFC分解电子邮件地址。这可能会带来更愉悦的体验，比如
指定的电子邮件地址'myemail@address，com'无效。你是说myemail@address.com'?
另请参阅验证电子邮件地址，包括注释。或比较电子邮件地址验证正则表达式。
Debugex演示
作为一个生动的演示，下面的怪物很好，但它仍然不能正确识别所有语法上有效的电子邮件地址：它可以识别多达四层的嵌套评论。
这是解析器的工作，但即使地址在语法上有效，也可能无法交付。有时你不得不求助于乡巴佬的方法，“嘿，你们，看着我们！”
// derivative of work with the following copyright and license:
// Copyright (c) 2004 Casey West. All rights reserved.
// This module is free software; you can redistribute it and/or
// modify it under the same terms as Perl itself.
// see http://search.cpan.org/~cwest/Email-Address-1.80/
private static string gibberish = @"
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|(?-xism:\\(?-xism:[^\x0A\x0D]))|)+)*\s*\)\s*))+)*\s*\)\s*)+
|\s+)*[^\x00-\x1F\x7F()<>\[\]:;@\,.<DQ>\s]+(?-xism:(?-xism:\
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\s*\((?:\s*(?-xism:(?-xism:(?>[^()\\]+))|(?-xism:\\(?-xism:[
^\x0A\x0D]))|(?-xism:\s*\((?:\s*(?-xism:(?-xism:(?>[^()\\]+)
)|(?-xism:\\(?-xism:[^\x0A\x0D]))|)+)*\s*\)\s*))+)*\s*\)\s*)
+|\s+)*)|(?-xism:(?-xism:(?-xism:\s*\((?:\s*(?-xism:(?-xism:
(?>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A\x0D]))|(?-xism:\s*\((
?:\s*(?-xism:(?-xism:(?>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A\
x0D]))|)+)*\s*\)\s*))+)*\s*\)\s*)+|\s+)*\[(?:\s*(?-xism:(?-x
ism:[^\[\]\\])|(?-xism:\\(?-xism:[^\x0A\x0D])))+)*\s*\](?-xi
sm:(?-xism:\s*\((?:\s*(?-xism:(?-xism:(?>[^()\\]+))|(?-xism:
\\(?-xism:[^\x0A\x0D]))|(?-xism:\s*\((?:\s*(?-xism:(?-xism:(
?>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A\x0D]))|)+)*\s*\)\s*))+
)*\s*\)\s*)+|\s+)*)))>(?-xism:(?-xism:\s*\((?:\s*(?-xism:(?-
xism:(?>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A\x0D]))|(?-xism:\
s*\((?:\s*(?-xism:(?-xism:(?>[^()\\]+))|(?-xism:\\(?-xism:[^
\x0A\x0D]))|)+)*\s*\)\s*))+)*\s*\)\s*)+|\s+)*))|(?-xism:(?-x
ism:(?-xism:(?-xism:(?-xism:\s*\((?:\s*(?-xism:(?-xism:(?>[^
()\\]+))|(?-xism:\\(?-xism:[^\x0A\x0D]))|(?-xism:\s*\((?:\s*
(?-xism:(?-xism:(?>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A\x0D])
)|)+)*\s*\)\s*))+)*\s*\)\s*)+|\s+)*(?-xism:[^\x00-\x1F\x7F()
<>\[\]:;@\,.<DQ>\s]+(?:\.[^\x00-\x1F\x7F()<>\[\]:;@\,.<DQ>\s
]+)*)(?-xism:(?-xism:\s*\((?:\s*(?-xism:(?-xism:(?>[^()\\]+)
)|(?-xism:\\(?-xism:[^\x0A\x0D]))|(?-xism:\s*\((?:\s*(?-xism
:(?-xism:(?>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A\x0D]))|)+)*\
s*\)\s*))+)*\s*\)\s*)+|\s+)*)|(?-xism:(?-xism:(?-xism:\s*\((
?:\s*(?-xism:(?-xism:(?>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A\
x0D]))|(?-xism:\s*\((?:\s*(?-xism:(?-xism:(?>[^()\\]+))|(?-x
ism:\\(?-xism:[^\x0A\x0D]))|)+)*\s*\)\s*))+)*\s*\)\s*)+|\s+)
*<DQ>(?-xism:(?-xism:[^\\<DQ>])|(?-xism:\\(?-xism:[^\x0A\x0D
])))+<DQ>(?-xism:(?-xism:\s*\((?:\s*(?-xism:(?-xism:(?>[^()\
\]+))|(?-xism:\\(?-xism:[^\x0A\x0D]))|(?-xism:\s*\((?:\s*(?-
xism:(?-xism:(?>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A\x0D]))|)
+)*\s*\)\s*))+)*\s*\)\s*)+|\s+)*))\@(?-xism:(?-xism:(?-xism:
(?-xism:\s*\((?:\s*(?-xism:(?-xism:(?>[^()\\]+))|(?-xism:\\(
?-xism:[^\x0A\x0D]))|(?-xism:\s*\((?:\s*(?-xism:(?-xism:(?>[
^()\\]+))|(?-xism:\\(?-xism:[^\x0A\x0D]))|)+)*\s*\)\s*))+)*\
s*\)\s*)+|\s+)*(?-xism:[^\x00-\x1F\x7F()<>\[\]:;@\,.<DQ>\s]+
(?:\.[^\x00-\x1F\x7F()<>\[\]:;@\,.<DQ>\s]+)*)(?-xism:(?-xism
:\s*\((?:\s*(?-xism:(?-xism:(?>[^()\\]+))|(?-xism:\\(?-xism:
[^\x0A\x0D]))|(?-xism:\s*\((?:\s*(?-xism:(?-xism:(?>[^()\\]+
))|(?-xism:\\(?-xism:[^\x0A\x0D]))|)+)*\s*\)\s*))+)*\s*\)\s*
)+|\s+)*)|(?-xism:(?-xism:(?-xism:\s*\((?:\s*(?-xism:(?-xism
:(?>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A\x0D]))|(?-xism:\s*\(
(?:\s*(?-xism:(?-xism:(?>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A
\x0D]))|)+)*\s*\)\s*))+)*\s*\)\s*)+|\s+)*\[(?:\s*(?-xism:(?-
xism:[^\[\]\\])|(?-xism:\\(?-xism:[^\x0A\x0D])))+)*\s*\](?-x
ism:(?-xism:\s*\((?:\s*(?-xism:(?-xism:(?>[^()\\]+))|(?-xism
:\\(?-xism:[^\x0A\x0D]))|(?-xism:\s*\((?:\s*(?-xism:(?-xism:
(?>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A\x0D]))|)+)*\s*\)\s*))
+)*\s*\)\s*)+|\s+)*))))(?-xism:\s*\((?:\s*(?-xism:(?-xism:(?
>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A\x0D]))|(?-xism:\s*\((?:
\s*(?-xism:(?-xism:(?>[^()\\]+))|(?-xism:\\(?-xism:[^\x0A\x0
D]))|)+)*\s*\)\s*))+)*\s*\)\s*)*)"
.Replace("<DQ>", "\"")
.Replace("\t", "")
.Replace(" ", "")
.Replace("\r", "")
.Replace("\n", "");
private static Regex mailbox =
new Regex(gibberish, RegexOptions.ExplicitCapture);
这是我使用的PHP代码。我选择这个解决方案是出于“误报比误报好”的精神，正如这里的另一位评论者所说的，并考虑到保持您的响应时间并降低服务器负载。。。当正则表达式可以消除大多数简单的用户错误时，真的不需要浪费服务器资源。如果你愿意，你可以随时通过发送测试邮件来跟进。
function validateEmail($email) {
return (bool) stripos($email,'@');
}
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