regex101: Matching email addresses per RFC5322

Definition Group(?(DEFINE) (?<addr_spec> (?&local_part) @ (?&domain) ) (?<local_part> (?&dot_atom) | (?&quoted_string) | (?&obs_local_part) ) (?<domain> (?&dot_atom) | (?&domain_literal) | (?&obs_domain) ) (?<domain_literal> (?&CFWS)? \[ (?: (?&FWS)? (?&dtext) )* (?&FWS)? \] (?&CFWS)? ) (?<dtext> [\x21-\x5a] | [\x5e-\x7e] | (?&obs_dtext) ) (?<quoted_pair> \\ (?: (?&VCHAR) | (?&WSP) ) | (?&obs_qp) ) (?<dot_atom> (?&CFWS)? (?&dot_atom_text) (?&CFWS)? ) (?<dot_atom_text> (?&atext) (?: \. (?&atext) )* ) (?<atext> [a-zA-Z0-9!#$%&'*+\/=?^_`{|}~-]+ ) (?<atom> (?&CFWS)? (?&atext) (?&CFWS)? ) (?<word> (?&atom) | (?&quoted_string) ) (?<quoted_string> (?&CFWS)? " (?: (?&FWS)? (?&qcontent) )* (?&FWS)? " (?&CFWS)? ) (?<qcontent> (?&qtext) | (?&quoted_pair) ) (?<qtext> \x21 | [\x23-\x5b] | [\x5d-\x7e] | (?&obs_qtext) ) # comments and whitespace (?<FWS> (?: (?&WSP)* \r\n )? (?&WSP)+ | (?&obs_FWS) ) (?<CFWS> (?: (?&FWS)? (?&comment) )+ (?&FWS)? | (?&FWS) ) (?<comment> $ (?: (?&FWS)? (?&ccontent) )* (?&FWS)? $ ) (?<ccontent> (?&ctext) | (?&quoted_pair) | (?&comment) ) (?<ctext> [\x21-\x27] | [\x2a-\x5b] | [\x5d-\x7e] | (?&obs_ctext) ) # obsolete tokens (?<obs_domain> (?&atom) (?: \. (?&atom) )* ) (?<obs_local_part> (?&word) (?: \. (?&word) )* ) (?<obs_dtext> (?&obs_NO_WS_CTL) | (?&quoted_pair) ) (?<obs_qp> \\ (?: \x00 | (?&obs_NO_WS_CTL) | \n | \r ) ) (?<obs_FWS> (?&WSP)+ (?: \r\n (?&WSP)+ )* ) (?<obs_ctext> (?&obs_NO_WS_CTL) ) (?<obs_qtext> (?&obs_NO_WS_CTL) ) (?<obs_NO_WS_CTL> [\x01-\x08] | \x0b | \x0c | [\x0e-\x1f] | \x7f ) # character class definitions (?<VCHAR> [\x21-\x7E] ) (?<WSP> [ \t] ) )

Group addr_spec(?<addr_spec> (?&local_part) @ (?&domain) )

(?&local_part)calls group local_part as a subroutine

@ the literal text @

(?&domain)calls group domain as a subroutine

Group local_part(?<local_part> (?&dot_atom) | (?&quoted_string) | (?&obs_local_part) )

1st Alternative (?&dot_atom)

(?&dot_atom)calls group dot_atom as a subroutine

2nd Alternative (?&quoted_string)

(?&quoted_string)calls group quoted_string as a subroutine

3rd Alternative (?&obs_local_part)

(?&obs_local_part)calls group obs_local_part as a subroutine

Group domain(?<domain> (?&dot_atom) | (?&domain_literal) | (?&obs_domain) )

1st Alternative (?&dot_atom)

(?&dot_atom)calls group dot_atom as a subroutine

2nd Alternative (?&domain_literal)

(?&domain_literal)calls group domain_literal as a subroutine

3rd Alternative (?&obs_domain)

(?&obs_domain)calls group obs_domain as a subroutine

Group domain_literal(?<domain_literal> (?&CFWS)? \[ (?: (?&FWS)? (?&dtext) )* (?&FWS)? \] (?&CFWS)? )

(?&CFWS)?optionally calls group CFWS as a subroutine

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

Non-Capturing Group(?: (?&FWS)? (?&dtext) )*

*repeats the group contents below any number of times:

(?&FWS)?optionally calls group FWS as a subroutine

(?&dtext)calls group dtext as a subroutine

(?&FWS)?optionally calls group FWS as a subroutine

\]the literal ] (93₁₀ / 135₈ / 5D₁₆)

(?&CFWS)?optionally calls group CFWS as a subroutine

Group dtext(?<dtext> [\x21-\x5a] | [\x5e-\x7e] | (?&obs_dtext) )

1st Alternative [\x21-\x5a]

Character Class[\x21-\x5a]

\x21-\x5aone character from ! (33₁₀) to Z (90₁₀) (case sensitive)

2nd Alternative [\x5e-\x7e]

Character Class[\x5e-\x7e]

\x5e-\x7eone character from ^ (94₁₀) to ~ (126₁₀)

3rd Alternative (?&obs_dtext)

(?&obs_dtext)calls group obs_dtext as a subroutine

Group quoted_pair(?<quoted_pair> \\ (?: (?&VCHAR) | (?&WSP) ) | (?&obs_qp) )

1st Alternative \\ (?: (?&VCHAR) | (?&WSP) )

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

Non-Capturing Group(?: (?&VCHAR) | (?&WSP) )

1st Alternative (?&VCHAR)

(?&VCHAR)calls group VCHAR as a subroutine

2nd Alternative (?&WSP)

(?&WSP)calls group WSP as a subroutine

2nd Alternative (?&obs_qp)

(?&obs_qp)calls group obs_qp as a subroutine

Group dot_atom(?<dot_atom> (?&CFWS)? (?&dot_atom_text) (?&CFWS)? )

(?&CFWS)?optionally calls group CFWS as a subroutine

(?&dot_atom_text)calls group dot_atom_text as a subroutine

(?&CFWS)?optionally calls group CFWS as a subroutine

Group dot_atom_text(?<dot_atom_text> (?&atext) (?: \. (?&atext) )* )

Group atext(?<atext> [a-zA-Z0-9!#$%&'*+\/=?^_`{|}~-]+ )

Group atom(?<atom> (?&CFWS)? (?&atext) (?&CFWS)? )

Group word(?<word> (?&atom) | (?&quoted_string) )

Group quoted_string(?<quoted_string> (?&CFWS)? " (?: (?&FWS)? (?&qcontent) )* (?&FWS)? " (?&CFWS)? )

Group qcontent(?<qcontent> (?&qtext) | (?&quoted_pair) )

Group qtext(?<qtext> \x21 | [\x23-\x5b] | [\x5d-\x7e] | (?&obs_qtext) )

Comment: comments and whitespace

Group FWS(?<FWS> (?: (?&WSP)* \r\n )? (?&WSP)+ | (?&obs_FWS) )

Group CFWS(?<CFWS> (?: (?&FWS)? (?&comment) )+ (?&FWS)? | (?&FWS) )

Group comment(?<comment> $ (?: (?&FWS)? (?&ccontent) )* (?&FWS)? $ )

Group ccontent(?<ccontent> (?&ctext) | (?&quoted_pair) | (?&comment) )

Group ctext(?<ctext> [\x21-\x27] | [\x2a-\x5b] | [\x5d-\x7e] | (?&obs_ctext) )

Comment: obsolete tokens

Group obs_domain(?<obs_domain> (?&atom) (?: \. (?&atom) )* )

Group obs_local_part(?<obs_local_part> (?&word) (?: \. (?&word) )* )

Group obs_dtext(?<obs_dtext> (?&obs_NO_WS_CTL) | (?&quoted_pair) )

Group obs_qp(?<obs_qp> \\ (?: \x00 | (?&obs_NO_WS_CTL) | \n | \r ) )

Group obs_FWS(?<obs_FWS> (?&WSP)+ (?: \r\n (?&WSP)+ )* )

Group obs_ctext(?<obs_ctext> (?&obs_NO_WS_CTL) )

Group obs_qtext(?<obs_qtext> (?&obs_NO_WS_CTL) )

Group obs_NO_WS_CTL(?<obs_NO_WS_CTL> [\x01-\x08] | \x0b | \x0c | [\x0e-\x1f] | \x7f )

Comment: character class definitions

Group VCHAR(?<VCHAR> [\x21-\x7E] )

Group WSP(?<WSP> [ \t] )

^start of line

(?&addr_spec)calls group addr_spec as a subroutine

$end of line

Global pattern flags

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

g modifier: global. Finds all matches instead of stopping after the first

Search reference

Regular Expression

(?(DEFINE)
    (?<addr_spec> (?&local_part) @ (?&domain) )
    (?<local_part> (?&dot_atom) | (?&quoted_string) | (?&obs_local_part) )
    (?<domain> (?&dot_atom) | (?&domain_literal) | (?&obs_domain) )
    (?<domain_literal> (?&CFWS)? \[ (?: (?&FWS)? (?&dtext) )* (?&FWS)? \] (?&CFWS)? )
    (?<dtext> [\x21-\x5a] | [\x5e-\x7e] | (?&obs_dtext) )
    (?<quoted_pair> \\ (?: (?&VCHAR) | (?&WSP) ) | (?&obs_qp) )
    (?<dot_atom> (?&CFWS)? (?&dot_atom_text) (?&CFWS)? )
    (?<dot_atom_text> (?&atext) (?: \. (?&atext) )* )
    (?<atext> [a-zA-Z0-9!#$%&'*+\/=?^_`{|}~-]+ )
    (?<atom> (?&CFWS)? (?&atext) (?&CFWS)? )
    (?<word> (?&atom) | (?&quoted_string) )
    (?<quoted_string> (?&CFWS)? " (?: (?&FWS)? (?&qcontent) )* (?&FWS)? " (?&CFWS)? )
    (?<qcontent> (?&qtext) | (?&quoted_pair) )
    (?<qtext> \x21 | [\x23-\x5b] | [\x5d-\x7e] | (?&obs_qtext) )
    # comments and whitespace
    (?<FWS> (?: (?&WSP)* \r\n )? (?&WSP)+ | (?&obs_FWS) )
    (?<CFWS> (?: (?&FWS)? (?&comment) )+ (?&FWS)? | (?&FWS) )
    (?<comment> \( (?: (?&FWS)? (?&ccontent) )* (?&FWS)? \) )
    (?<ccontent> (?&ctext) | (?&quoted_pair) | (?&comment) )
    (?<ctext> [\x21-\x27] | [\x2a-\x5b] | [\x5d-\x7e] | (?&obs_ctext) )
    # obsolete tokens
    (?<obs_domain> (?&atom) (?: \. (?&atom) )* )
    (?<obs_local_part> (?&word) (?: \. (?&word) )* )
    (?<obs_dtext> (?&obs_NO_WS_CTL) | (?&quoted_pair) )
    (?<obs_qp> \\ (?: \x00 | (?&obs_NO_WS_CTL) | \n | \r ) )
    (?<obs_FWS> (?&WSP)+ (?: \r\n (?&WSP)+ )* )
    (?<obs_ctext> (?&obs_NO_WS_CTL) )
    (?<obs_qtext> (?&obs_NO_WS_CTL) )
    (?<obs_NO_WS_CTL> [\x01-\x08] | \x0b | \x0c | [\x0e-\x1f] | \x7f )
    # character class definitions
    (?<VCHAR> [\x21-\x7E] )
    (?<WSP> [ \t] )
)
^(?&addr_spec)$

New

 Valid
-------
first.last@iana.org
1234567890123456789012345678901234567890123456789012345678901234@iana.org
"first\"last"@iana.org
"first@last"@iana.org
"first\\last"@iana.org
x@x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x2
1234567890123456789012345678901234567890123456789012345678@12345678901234567890123456789012345678901234567890123456789.12345678901234567890123456789012345678901234567890123456789.123456789012345678901234567890123456789012345678901234567890123.iana.org
first.last@[12.34.56.78]
first.last@[IPv6:::12.34.56.78]
first.last@[IPv6:::b3:b4]
first.last@[IPv6:::]
first.last@[IPv6:1111:2222:3333::4444:12.34.56.78]
"first\last"@iana.org
user+mailbox@iana.org
customer/department@iana.org 
customer/department=shipping@iana.org
"Doug \"Ace\" L."@iana.org
+1~1+@iana.org
{_test_}@iana.org
"[[ test ]]"@iana.org
"test&#13;&#10; blah"@iana.org
(foo)cal(bar)@(baz)iamcal.com(quux)
cal(woo(yay)hoopla)@iamcal.com
cal(foo\@bar)@iamcal.com
cal(foo\)bar)@iamcal.com
first(Welcome to&#13;&#10; the ("wonderful" (!)) world&#13;&#10; of email)@iana.org
pete(his account)@silly.test(his host)
c@(Chris's host.)public.example

 Invalid
---------
first@...........com
first.last@sub.do,com
first\@last@iana.org
first.last
.first.last@iana.org
first.last.@iana.org
"first"last"@iana.org
"""@iana.org
first\\@last@iana.org
Doug\ \"Ace\"\ Lovell@iana.org
()[]\;:,><@iana.org
test@.
test@[123.123.123.123
test@123.123.123.123]

Regular Expressions 101

Regular Expression

Extraction