time: 2014-07-21 01:47:02
url: http://www.multipleincom.esy.es/web/ipn/ipn.php
result: ERROR : email error: Operation now in progress(115) [CProductMailer]
=====
[CSystem:time]
-----------
2014-07-21 01:47:02
====
[CIpnReceiver:authx-host]
-----------
www.multipleincom.esy.es
====
[CIpnReceiver:authx-path]
-----------
/web/sim/auth_ipn.php
====
[CIpnReceiver:authx-domain]
-----------
www.multipleincom.esy.es
====
[CIpnReceiver:authx-port]
-----------
80
====
[CIpnReceiver:post-from-paypal]
-----------
SIM_KEY=1kdjgircmbnoskhgkr&txn_id=ndlkpBRWmeZzovhfIzN&business=sngeetong%40yahoo.com.sg&item_name=Sample+Product+001&item_number=product-001&mc_gross=12.34&mc_currency=USD&notify_url=http%3A%2F%2Fwww.multipleincom.esy.es%2Fweb%2Fipn%2Fipn.php&payer_email=wargamon%40gmail.com&last_name=Aries&first_name=War
====
[CIpnReceiver:reply-to-paypal]
-----------
POST /web/sim/auth_ipn.php HTTP/1.0
Host: www.multipleincom.esy.es
Content-Type: application/x-www-form-urlencoded
Content-Length: 327

cmd=_notify-validate&SIM_KEY=1kdjgircmbnoskhgkr&txn_id=ndlkpBRWmeZzovhfIzN&business=sngeetong%40yahoo.com.sg&item_name=Sample+Product+001&item_number=product-001&mc_gross=12.34&mc_currency=USD&notify_url=http%3A%2F%2Fwww.multipleincom.esy.es%2Fweb%2Fipn%2Fipn.php&payer_email=wargamon%40gmail.com&last_name=Aries&first_name=War
====
[CIpnReceiver:result]
-----------
OK
====
[CIpnReceiver:paypal-status]
-----------
VERIFIED
====
[CIpnReceiver:response-from-paypal]
-----------
HTTP/1.1 200 OK
Server: nginx
Date: Mon, 21 Jul 2014 01:47:03 GMT
Content-Type: text/html
Connection: close
Vary: Accept-Encoding
X-Powered-By: PHP/5.3.28

VERIFIED
====
[Transaction:SIM_KEY]
-----------
1kdjgircmbnoskhgkr
====
[Transaction:txn_id]
-----------
ndlkpBRWmeZzovhfIzN
====
[Transaction:business]
-----------
sngeetong@yahoo.com.sg
====
[Transaction:item_name]
-----------
Sample Product 001
====
[Transaction:item_number]
-----------
product-001
====
[Transaction:mc_gross]
-----------
12.34
====
[Transaction:mc_currency]
-----------
USD
====
[Transaction:notify_url]
-----------
http://www.multipleincom.esy.es/web/ipn/ipn.php
====
[Transaction:payer_email]
-----------
wargamon@gmail.com
====
[Transaction:last_name]
-----------
Aries
====
[Transaction:first_name]
-----------
War
====
[CProductInfoSub:item_number]
-----------
product-001
====
[Product-Info:item_name]
-----------
Sample Product 001
====
[Product-Info:amount]
-----------
12.34
====
[Product-Info:currency_code]
-----------
USD
====
[Product-Info:Subject]
-----------
Thank you for purchasing our E-book! (##item_number##)
====
[Product-Info:Body]
-----------
This is the email template<Removed HTML portion, comment too long>

====
[Product-Info:files]
-----------
/home/u567322489/public_html/web/products/product-001/files/sample-001.pdf
/home/u567322489/public_html/web/products/product-001/files/sample-001.txt
/home/u567322489/public_html/web/products/product-001/files/sample-001.png
====
[CProductInfoSub:result]
-----------
OK
====
[CProductMailer:smtp-log]
-----------
CEmail v1.40

====
[CProductMailer:result]
-----------
FAIL
====
[CSystem:_error_]
-----------
email error: Operation now in progress(115) [CProductMailer]
====

Looks like the email server is not responding immediately. This isn't a simple case where I can point out the cause right away. The easiest and quickest solution is use other email servers.

If you really want to find the cause, forget about the script first and then do some testing directly on the email server. First make a successful mail delivery by any means. Second, compare the configuration of the successful case with that of the script. You may find misconfigurations you have overlooked or methods to adjust the configuration to quirks of the the email server.