Hi My mail sending function which was hosted in client's server was working previously. But suddenly from yesterday it is not working. The below error appears. can any one suggest what is the reason if any settings were changed? -----Error-------- SMTP -> get_lines(): $data was "" SMTP -> get_lines(): $str is "220-cp.webbingxchange.net ESMTP Exim 4.69 #1 Tue, 04 Aug 2009 12:12:25 +0800 " SMTP -> get_lines(): $data is "220-cp.webbingxchange.net ESMTP Exim 4.69 #1 Tue, 04 Aug 2009 12:12:25 +0800 " SMTP -> get_lines(): $data was "220-cp.webbingxchange.net ESMTP Exim 4.69 #1 Tue, 04 Aug 2009 12:12:25 +0800 " SMTP -> get_lines(): $str is "220-We do not authorize the use of this system to transport unsolicited, " SMTP -> get_lines(): $data is "220-cp.webbingxchange.net ESMTP Exim 4.69 #1 Tue, 04 Aug 2009 12:12:25 +0800 220-We do not authorize the use of this system to transport unsolicited, " SMTP -> get_lines(): $data was "220-cp.webbingxchange.net ESMTP Exim 4.69 #1 Tue, 04 Aug 2009 12:12:25 +0800 220-We do not authorize the use of this system to transport unsolicited, " SMTP -> get_lines(): $str is "220 and/or bulk e-mail. " SMTP -> get_lines(): $data is "220-cp.webbingxchange.net ESMTP Exim 4.69 #1 Tue, 04 Aug 2009 12:12:25 +0800 220-We do not authorize the use of this system to transport unsolicited, 220 and/or bulk e-mail. " SMTP -> FROM SERVER: 220-cp.webbingxchange.net ESMTP Exim 4.69 #1 Tue, 04 Aug 2009 12:12:25 +0800 220-We do not authorize the use of this system to transport unsolicited, 220 and/or bulk e-mail. SMTP -> get_lines(): $data was "" SMTP -> get_lines(): $str is "250-cp.webbingxchange.net Hello localhost [219.94.68.54] " SMTP -> get_lines(): $data is "250-cp.webbingxchange.net Hello localhost [219.94.68.54] " SMTP -> get_lines(): $data was "250-cp.webbingxchange.net Hello localhost [219.94.68.54] " SMTP -> get_lines(): $str is "250-SIZE 52428800 " SMTP -> get_lines(): $data is "250-cp.webbingxchange.net Hello localhost [219.94.68.54] 250-SIZE 52428800 " SMTP -> get_lines(): $data was "250-cp.webbingxchange.net Hello localhost [219.94.68.54] 250-SIZE 52428800 " SMTP -> get_lines(): $str is "250-AUTH PLAIN LOGIN " SMTP -> get_lines(): $data is "250-cp.webbingxchange.net Hello localhost [219.94.68.54] 250-SIZE 52428800 250-AUTH PLAIN LOGIN " SMTP -> get_lines(): $data was "250-cp.webbingxchange.net Hello localhost [219.94.68.54] 250-SIZE 52428800 250-AUTH PLAIN LOGIN " SMTP -> get_lines(): $str is "250-STARTTLS " SMTP -> get_lines(): $data is "250-cp.webbingxchange.net Hello localhost [219.94.68.54] 250-SIZE 52428800 250-AUTH PLAIN LOGIN 250-STARTTLS " SMTP -> get_lines(): $data was "250-cp.webbingxchange.net Hello localhost [219.94.68.54] 250-SIZE 52428800 250-AUTH PLAIN LOGIN 250-STARTTLS " SMTP -> get_lines(): $str is "250 HELP " SMTP -> get_lines(): $data is "250-cp.webbingxchange.net Hello localhost [219.94.68.54] 250-SIZE 52428800 250-AUTH PLAIN LOGIN 250-STARTTLS 250 HELP " SMTP -> FROM SERVER: 250-cp.webbingxchange.net Hello localhost [219.94.68.54] 250-SIZE 52428800 250-AUTH PLAIN LOGIN 250-STARTTLS 250 HELP SMTP -> get_lines(): $data was "" SMTP -> get_lines(): $str is "334 VXNlcm5hbWU6 " SMTP -> get_lines(): $data is "334 VXNlcm5hbWU6 " SMTP -> get_lines(): $data was "" SMTP -> get_lines(): $str is "334 UGFzc3dvcmQ6 " SMTP -> get_lines(): $data is "334 UGFzc3dvcmQ6 " SMTP -> get_lines(): $data was "" SMTP -> get_lines(): $str is "235 Authentication succeeded " SMTP -> get_lines(): $data is "235 Authentication succeeded " SMTP -> get_lines(): $data was "" SMTP -> get_lines(): $str is "250 OK " SMTP -> get_lines(): $data is "250 OK " SMTP -> FROM SERVER: 250 OK SMTP -> get_lines(): $data was "" SMTP -> get_lines(): $str is "501 <>: missing or malformed local part " SMTP -> get_lines(): $data is "501 <>: missing or malformed local part " SMTP -> FROM SERVER: 501 <>: missing or malformed local part SMTP -> ERROR: RCPT not accepted from server: 501 <>: missing or malformed local part SMTP -> get_lines(): $data was "" SMTP -> get_lines(): $str is "250 Reset OK " SMTP -> get_lines(): $data is "250 Reset OK " SMTP -> FROM SERVER: 250 Reset OK Message could not be sent. Mailer Error: SMTP Error: The following recipients failed: -------------------