^ asserts position at start of a lineLines are delimited by \n
From: matches the characters From: literally (case sensitive)
\s matches any whitespace character (equal to [\r\n\t\f\v ])
Match a single character present in the list below [A-Za-z]+
+ Quantifier — Matches between one and unlimited times, as many times as possible, giving back as needed (greedy)
A-Z a single character in the range between A (index 65) and Z (index 90) (case sensitive)
a-z a single character in the range between a (index 97) and z (index 122) (case sensitive)
\s matches any whitespace character (equal to [\r\n\t\f\v ])
Match a single character present in the list below [A-Za-z]+
+ Quantifier — Matches between one and unlimited times, as many times as possible, giving back as needed (greedy)
A-Z a single character in the range between A (index 65) and Z (index 90) (case sensitive)
a-z a single character in the range between a (index 97) and z (index 122) (case sensitive)
1st Capturing Group (\s[A-Za-z]+)?
? Quantifier — Matches between zero and one times, as many times as possible, giving back as needed (greedy)
\s matches any whitespace character (equal to [\r\n\t\f\v ])
Match a single character present in the list below [A-Za-z]+
2nd Capturing Group (\s[A-Za-z]+)?
? Quantifier — Matches between zero and one times, as many times as possible, giving back as needed (greedy)
\s matches any whitespace character (equal to [\r\n\t\f\v ])
Match a single character present in the list below [A-Za-z]+
\s matches any whitespace character (equal to [\r\n\t\f\v ])
< matches the character < literally (case sensitive)
Match a single character present in the list below [A-Za-z]+
\. matches the character . literally (case sensitive)
Match a single character present in the list below [A-Za-z]+
@domain matches the characters @domain literally (case sensitive)
\. matches the character . literally (case sensitive)
com> matches the characters com> literally (case sensitive)
g modifier: global. All matches (don't return after first match)
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)