regex101: PCRE2 (PHP) Match Workspace

Pro

^start of line

Non-Capturing Group(?:-.*\n){3}

{3}repeats the group contents below exactly 3 times:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

.*any character (except for line terminators), repeated any number of times

\na line-feed (newline) character (ASCII 10)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Group 1((?:.*\n(?!-+ Forwarded message).*)*)

Non-Capturing Group(?:.*\n(?!-+ Forwarded message).*)*

*repeats the group contents below any number of times:

.*any character (except for line terminators), repeated any number of times

\na line-feed (newline) character (ASCII 10)

Negative Lookahead(?!-+ Forwarded message)

-+the literal - (45₁₀ / 55₈ / 2D₁₆) , repeated at least once

Forwarded messagethe literal text Forwarded message (case sensitive)

.*any character (except for line terminators), repeated any number of times

Global pattern flags

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

25 tokens

Regular Expression

^(?:-.*\n){3}-((?:.*\n(?!-+ Forwarded message).*)*)

New

-match one
-match two
-match three
-and a bunch of notes here, potentially with more than 1 line or newlines included 
and there may be hyphens in this text as well

This is a - text

- match five
---------- Forwarded message ----------
From:....

Substitution

-match one
-match two
-match three
-and a bunch of notes here, potentially with more than 1 line or newlines included 
and there may be hyphens in this text as well

This is a - text

- match five
---------- Forwarded message ----------
From:....