emails we send out from shopify to our customers such as the shipping notification with the tracking ID are being rejected by the customers servers. Depending on their provider we get back messages such as the ones listed below. According to this website shopify email servers are being blacklisted on quite a few spam filters: http://zy0.de/q/22.214.171.124
What can I do in order to fix this? Or is this a shopify issue?
host mx0.webpack.hosteurope.de[X.X1X.X] refused to
talk to me: 550-REJECT: X.X.X.X is in ix.dnsbl.manitu.net :
550-Your e-mail service was detected by mx-ha.web.de (NiX Spam) as spamming
at 550-Tue, 14 May 2019 13:37:16 +0200. Your admin should visit 550
Relay access denied (in reply to RCPT TO command)
Unfortunately, messages from [X.X.X.X] weren't sent.
Please contact your Internet service provider since part of their network
is on our block list (S3150). You can also refer your provider to
[AM5EUR03FT030.eop-EUR03.prod.protection.outlook.com] (in reply to MAIL