Hi- I am attempting to parse email headers using the boost regex library. I would prefer that each email address in the TO field (delimited by a comma) would be placed into a vector<string>. Currently, I am able to obtain the entire to line (all the to addresses). I can use another regular expression to seperate it out but I'd rather do it all in one. However, If I try to add another more to this I get an exception: "Max regex search depth exceeded." I am assuming that this is because I've created a infinite loop. I'm not sure how to extend this expression to place every email address in the vector seperatly. Thanks here's my code snippet: char * expression_text = //Any possible leading whitespace: "^[ ]*" //The "To" field name in any case: "TO" //Any more whitespace: "[ ]*" //Then a colon: ":" //More white space potentially "[ ]*" //Everything here is an address up to "\r\n"; "([-@_\\.\"<>A-Za-z0-9]+),?"; //Create the expression class to use: RegEx expression(expression_text, true); //Attempt to grep the mail_buffer: int num_recv = 0; try { num_recv = expression.Split(to, mail_buffer); } catch (...){ //throw some exception } }