这个Email验证的正则表达式基本符合RFC3521规范，缺少ipv6部分的验证。

Mail=("[\\x20-\\x21\\x23-\\x5B\\x5D-\\x7E]*"|"(\\\\[\\x20-\\x7E])*"|^[-!#$%&\'*+/0-9=?A-Z\\^_`a-z{|}~]+(.[-!#$%&\'*+/0-9=?A-Z\\^_`a-z{|}~]+)*)@([a-zA-Z0-9]+([\\-\\da-zA-Z]*[a-zA-Z0-9]+)*(\\.[a-zA-Z\\d]+([\\-\\da-zA-Z]*[a-zA-Z0-9]+)*)*|[\\[]((1[0-9][0-9]|25[0-5]|2[0-4][0-9]|0[0-9][0-9]|00[0-9]|[0-9][0-9]|[0-9])\\.(1[0-9][0-9]|25[0-5]|2[0-4][0-9]|0[0-9][0-9]|00[0-9]|[0-9][0-9]|[0-9])\\.(1[0-9][0-9]|25[0-5]|2[0-4][0-9]|0[0-9][0-9]|00[0-9]|[0-9][0-9]|[0-9])\\.(1[0-9][0-9]|25[0-5]|2[0-4][0-9]|0[0-9][0-9]|00[0-9]|[0-9][0-9]|[0-9]))[\\]]|((1[0-9][0-9]|25[0-5]|2[0-4][0-9]|0[0-9][0-9]|00[0-9]|[0-9][0-9]|[0-9])\\.(1[0-9][0-9]|25[0-5]|2[0-4][0-9]|0[0-9][0-9]|00[0-9]|[0-9][0-9]|[0-9])\\.(1[0-9][0-9]|25[0-5]|2[0-4][0-9]|0[0-9][0-9]|00[0-9]|[0-9][0-9]|[0-9])\\.(1[0-9][0-9]|25[0-5]|2[0-4][0-9]|0[0-9][0-9]|00[0-9]|[0-9][0-9]|[0-9])))

RFC3521中的相关定义：

Domain         = sub-domain *("." sub-domain)

sub-domain     = Let-dig [Ldh-str]

Let-dig        = ALPHA / DIGIT

Ldh-str        = *( ALPHA / DIGIT / "-" ) Let-dig

address-literal  = "[" ( IPv4-address-literal /

IPv6-address-literal /

General-address-literal ) "]"

; See Section 4.1.3

Mailbox        = Local-part "@" ( Domain / address-literal )

Local-part     = Dot-string / Quoted-string

; MAY be case-sensitive

Dot-string     = Atom *("."  Atom)

Atom           = 1*atext

Quoted-string  = DQUOTE *QcontentSMTP DQUOTE

QcontentSMTP   = qtextSMTP / quoted-pairSMTP

quoted-pairSMTP  = %d92 %d32-126

; i.e., backslash followed by any ASCII

; graphic (including itself) or SPace

qtextSMTP      = %d32-33 / %d35-91 / %d93-126

; i.e., within a quoted string, any

; ASCII graphic or space is permitted

; without blackslash-quoting except

; double-quote and the backslash itself.