Duplicate sales emails

Question

It all started when we moved the site and the email sending to a new server. Since then the new sale emails are sent twice, both to the customer and store owner. We are running Magento ver. 1.9.2.4

I tried out all the solutions described here, here and here.

Here is what I know so far:

• there are no orphan records left on the Recipients table
• there are no duplicate emails created in the database
• cron is running and there are no duplicate crontasks created
• I have set the copy that is sent to the store to BCC, I tried the Separate copy method but it's the same issue
• Initially we used SMTP pro extension, as it was required by the old host company, the issue started when I changed these settings to the new server's settings. I disabled and uninstalled the extension, but it keeps sending duplicate emails.

• There is a little difference between the two emails:

  1. visually the payment method is missing from one the emails

  2. comparing the two sources I found the following differences in the head section:

     2: Received: by 10.25.25.18 with SMTP id 18csp557327lfz;
     3: Thu, 9 Jun 2016 14:08:03 -0700 (PDT)
     4: X-Received: by 10.140.96.199 with SMTP id k65mr9670671qge.27.1465506483853;
     5: Thu, 09 Jun 2016 14:08:03 -0700 (PDT)
     
     2: Received: by 10.25.25.18 with SMTP id 18csp557131lfz;
     3: Thu, 9 Jun 2016 14:07:25 -0700 (PDT)
     4: X-Received: by 10.140.85.106 with SMTP id m97mr11482818qgd.41.1465506445409;
     5: Thu, 09 Jun 2016 14:07:25 -0700 (PDT)
     
     
     8: by mx.google.com with ESMTPS id s5si4428297qkc.169.2016.06.09.14.08.03
     8: by mx.google.com with ESMTPS id v124si1449328qhc.120.2016.06.09.14.07.24
     
     
     16: Message-Id:        
     <5759dab3.0577370a.5244e.45daSMTPIN_ADDED_MISSING@mx.google.com>
     
     16: Message-Id:
     <5759da8d.82fa8c0a.780ba.ffff8a35SMTPIN_ADDED_MISSING@mx.google.com>
     
     
     23: bh=dkKnBT4pJtbsDHYzbIX730M5P1u+x/BPP7K3dCdYeCE=; b=bKu0SmXGmuiU2GyuQbIcrR7OSH CRfnmNgcu8fGMu2ep8IEisxwyUQfFqLr7u+Exv7MBqtinYdTgFs1C6RuPJUJoEDKDLQAgd6tz3Joe O5UObhunwfkEj1r8hLQofHr0ohyq8aaCGwAe2QP6pJaIAaLhouo2Otwq/e/KnHL7Xt77D6HYKFyr8 ep3MBAVnRld4dBVN0InxOa1L3IACKFwn2x5nHsxvoxYot5+ECkfOsKGSkL7p/LHs4VLhTL1CE4BoI wk3r0u5WL7FRFWaHJyKp8Ey5ZNOvtdY0/bU9jgCOyuXLEmPbyuobGMXFHbUwjDKv8LD0OAjlqY7eZ Ai1YUnTg==;
     29: Received: from c11-92.tlh.ro ([86.105.187.92]:59678 helo=localhost)
     
     23: bh=Mfeb2i5EeCiNoEabwwaBRo8bnT4HLAR5z32ZZKIh8oo=; b=Izrj7xp7XVH0efHVJAFKpOIl1Y PNTYKwXkPmlu0QW9CNq0XNha3W1Rf/TD3qNMQxvkbn25G71nOseLQxORPcBItPDp3QJWzi7t8mDUH wccJjVfIvHoq7T+tuhB2vp64g6IMGwQ7XoGXXDreoumLQxv2yk/CwRneEjgO3fuBJbtnSggVMVWM0 RY7I8rMgIvHUeveZxjcL+DMKP1k7cHXTFrQj/0jnFqnjMFw3FNKt5QOSZMG2/Wem3I/V5VzOI2iEV aAXtbxdhkI94nuRueQ3b2UndL6MpQVjK+nS4dwfp9KPYU+pAXVusvreLloSAhSw+kcWgsUBMmyIe8 AcxxJoxQ==;
     29: Received: from c11-92.tlh.ro ([86.105.187.92]:59460 helo=localhost)
     
     
     32:     id 1bB7BJ-0005mx-Vc; Fri, 10 Jun 2016 00:08:02 +0300
     32:     id 1bB7Ah-0005mG-EH; Fri, 10 Jun 2016 00:07:23 +0300
     

It seems that it is creating two separate emails with different ID's for some reason. I am struggling with this for over a week now and I just can't find out what is wrong.

Answer 1

I am not sure there is an option for this. I had the same problem. It was caused by diverged php-fpm and php-cli configurations. PHP-FPM had Memcached as a caching backend activated and the memcached extension enabled. PHP-CLI had the same caching backend activated but had no memcached extension, which caused Magento to fall back to the File cache backend. I am not 100% sure why this happens, but I think the cache is somehow involved in the email sending process.

Maybe check if there is a similar problem with your hoster.