$re = '/\b[1-9](?:,?\d){7}\b/m';
$str = 'From RE: Markitwire: 120432889: Mx: 24,693,059 i need to get 24693059
From Automatic reply: Auftrag zur Übertragung IRD Ref-Nr. MMX_23497152 need to get 23497152
From FW: CGMSE 2019-2X A1AN XS2022418672 Contract 24663537 need to get 24663537
From RE: BBVA-MAD MMX_24644644 + MMX_24644645 need to get 24644644, 24644645
TGF00023242526';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php