Is it syntactically correct to delimit multiple email recipients in the "To" header of an email with spaces only or do I need to use another delimiter (a semicolon or the like)? Example (MIME data reads as follows): Date: Mon, 04 Oct 2010 06:14:16 +0200 From: [email protected] To: [email protected] [email protected] [email protected] Subject: Test Subject The above will be processed by many email processing applications, but I need to know whether it's correct according to standard (RFC). Unfortunately I didn't find anything useful on the internet so far. Thanks a million for your help!