Hi and welcome do devnet,

found some issues in your regexp

DATE:(\\\d{1,2}):(\\\d) should be DATE:(\\\d{1,2}):(\\\d{2}) (\\\d{1,2})\\/(\\\d)\\/(\\\d{2,4}) should be (\\\d{1,2})\\/(\\\d{1,2})\\/(\\\d{2,4}) in your regexp SEND-ID follows AUTH but in your string is not true

BTW a simple solution to make debug easier could be to split the string in lines and process a line at time