/
(?:\s*from\s(?:(?:([^\(\n]*?)\s)|(\[[^\]]*\]))?(?:\((?:(?:((?!HELO|EHLO)[^\s]*)|(?:(?:EHLO)|(?:HELO)))?(?:[\s\w\.]*(?:(?:\[([^\]]*)\])|([^\)\s]*))\))))?(?:\{.*\})?)?
\s*(?:(?:client\s)?[\(\{\[]+([^\)\}\]]*)[\)\}\]]+\;?(?:\{.*\})?)?
(?:[\s\n]*)
(?:\s*(?:by(?:(?:.*?)(?:\;|(?:[\r\n]+))))(?!.*with))?
(?:\s*(?:by\s[^\;]*\)?)(?=.*with)\s*)?
(?:with\s*(?:((?:[^\n;]*))(?:.*\;)?))?
(?:[\s\n]*)?
(?:\(?envelope-from\s*([^\n]*)\;?\)?)?
(?:\s*id[^;]*\;?)?
(?:[\s\n]*)?
(?:for\s([^\;]*)\;)?
(?:[\s\n]*)?
(?:\(.*\)\;)?(?:[\s\n])?
([^\(]+)?
(?:\(?envelope-from\s*([^\n]*)\;?\)?)?
/
mx