explained email regex

gistfile1.txt

/\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i  full regex
/	                             start of regex
\A	                             atch start of a string
[\w+\-.]+	                     at least one word character, plus, hyphen, or dot
@	                             literal “at sign”
[a-z\d\-.]+	                     at least one letter, digit, hyphen, or dot
\.	                             literal dot
[a-z]+	                             at least one letter
\z	                             match end of a string
/	                             end of regex
i	                             case insensitive