regex101: Simple but powerful email

^start of line

Character Class[a-z0-9]+

+matches at least one character from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case insensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Non-Capturing Group(?:[.\-_'+][a-z0-9]+)*

*repeats the group contents below any number of times:

Character Class[.\-_'+]

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

'the literal ' (39₁₀ / 47₈ / 27₁₆)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

Character Class[a-z0-9]+

+matches at least one character from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case insensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

@the literal @ (64₁₀ / 100₈ / 40₁₆)

Group 1([a-z0-9]+(?:[-][a-z0-9]+)*\.)+

+repeats the group contents below at least once:

Character Class[a-z0-9]+

+matches at least one character from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case insensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Non-Capturing Group(?:[-][a-z0-9]+)*

*repeats the group contents below any number of times:

Character Class[-]

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Character Class[a-z0-9]+

+matches at least one character from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case insensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[a-z]{2,}

{2,}matches at least 2 characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case insensitive)

$end of line

Global pattern flags

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

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

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

Search reference

Regular Expression

^[a-z0-9]+(?:[.\-_'+][a-z0-9]+)*@([a-z0-9]+(?:[-][a-z0-9]+)*\.)+[a-z]{2,}$

Test String
New

Valid emails:
user@domain.ru
na_me.lastname@subdomain.domain.ru
name-lastname@7.sub-sub-domain.subdomain.domain.ru
ni+ck'name-name.lastname@d.oma-in-domain.ru

Invalid addresses in the user section:
.user@domain.ru
user.@domain.ru
-user@domain.ru
user-@domain.ru
us..er@domain.ru
us--er@domain.ru

Invalid addresses in the domain section:
user@-domain.ru
user@.subdomain.domain.ru
user@subdomain-.domain.ru
user@subdomain..domain.ru
user@domain.-domain.ru
user@dom--ain.ru

Regular Expression

Test StringNew

Test String
New