Just a thought, and may be wrong, but as RCPT TO in rfc 2821 (http://www.rfc-editor.org/rfc/rfc2821.txt) Only one layer of backets is used? -----Original Message----- From: Dan Mashal [mailto:dmashal@xxxxxxxxxxxxxx] Sent: 23 June 2008 19:42 To: php-windows@xxxxxxxxxxxxx Subject: PHP Mail 501 error Hello, We are running MediaWiki on PHP 5.2.6 with Apache for Windows. Every time we try to use an IIS mail server as an MTA we receive a 501 error. When we use a Unix postfix based MTA it works fine. Could anyone please tell me what I need to do to modify my PHP.ini to get this to work? We have tried the workaround for Exchange 2003 as described in this article by Microsoft: http://support.microsoft.com/?id=291828 But this fixes a 501 in the HELO. The problem here is the rcpt to. It comes up as the following: 2008-06-23 17:39:58 10.1.100.80 xxx SMTPSVC1 xxxx xxxxxxxx 0 RCPT - +TO:<DanMashal+<dmashal@xxxxxxxxxxxxxx>> 501 0 27 44 0 SMTP - - - - Could anyone please provide me with some much needed insight on this problem? I have been searching the web and have found a few workarounds but none that actually work. Thanks, Dan * * * * * * * * * * * * Help protect the environment - please don't print this email unless you really need to. * * * * * * * * * * * * This communication is from City of York Council. The information contained within, and in any attachment(s), is confidential and legally privileged. It is for the exclusive use of the intended recipient(s). If you are not the intended recipient(s), please note that any form of distribution, copying or use of this communication, or the information within, is strictly prohibited and may be unlawful. Equally, you must not disclose all, or part, of its contents to any other person. If you have received this communication in error, please return it immediately to the sender, then delete and destroy any copies of it. City of York Council disclaims any liability for action taken in reliance on the content of this communication. -- PHP Windows Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php