M не имеет RegEx, но можно написать функции проверки с более подробным кодом.
Например, вот один из способов написать функцию проверки, аналогичную вашему RegEx:
let
IsValidEmail = (input as text) =>
let
name = Text.BeforeDelimiter(input,"@",{0,RelativePosition.FromEnd}),
ext = Text.AfterDelimiter(input,".",{0,RelativePosition.FromEnd}),
domain = Text.BetweenDelimiters(input,name&"@","."&ext),
return =
Text.Length(name) > 0 and
Text.Length(domain) > 0 and
Text.Length(ext) > 1 and Text.Length(ext) < 6 and
name = Text.Select(name, {"a".."z","A".."Z","0".."9","_","-","."}) and
domain = Text.Select(domain, {"a".."z","A".."Z","0".."9","_","-","."}) and
ext = Text.Select(ext, {"a".."z","A".."Z"})
in
return
in
IsValidEmail