I hope someone can help us or can give us a tip or direction how to solve the next problem?
We started using the standard build in email from magento 2. Only we found out a lot/most emails that customers would receive goes directly in their spam folder because fe. Google mention "Gmail cannot verify that this message was sent by copyshopdehaan.nl (and not by a spammer)"
After a heavy discussion for 4 weeks with our supplier they recommended a SMTP extension so we went for Aitoc's SMTP which being installed. After installing and we did setup all credentials/ports etc we got only failure notices after magento 2 sends automatic order, invoice, contactform emails, all came back with error code 550;
18.104.22.168 failed after I sent the message. Remote host said: 550 Messages should have one or no Content-Type headers, not 2.
--- Below this line is a copy of the message. Return-Path: Received: (qmail 2976 invoked from network); 27 Aug 2020 16:49:59 -0000 Received: from unknown (HELO 22.214.171.124) (firstname.lastname@example.org@[126.96.36.199]) by 172.17.0.4 with ESMTPSA (DHE-RSA-AES128-GCM-SHA256 encrypted, authenticated); 27 Aug 2020 16:49:59 -0000 Date: Thu, 27 Aug 2020 16:49:55 +0000 From: CustomerSupport Copyshop De Haan
Please if you have some tips, thoughts etc we would appreciate these! Thanks in advance