Access to this mail system has been blocked for xxxx due to spam activity
Following up with support team on this issue for more than 4 weeks now. Looks like godaddy is meant only for the 2-3 page websites. We have hosted ERP application on VPS and using sendmail to send legitimate notifications to our customers. Despite of removing email blocks 2 times again there is block today. When we call customer support, they would just say wait for 24hrs. But nobody knows the exact reason for block. Really frustrating experience, godaddy is not for professional portals, planning to move to AWS.
Imagine my customers are not getting important notifications since 1 day, godaddy do not have that professional support.
I find that AWS has it's own set of unique issues. Based on my experience, using a dedicated services like MailChimp, SendGrid or MailGun works the best because they have policies that keeps there server/domain reputation clean. This method works for most users because they never have to worry about networking/firewall (out going port, huge issue with GoDaddy) etc... Easy to set up.
My usual 2nd option is using gmail SMTP... A little more difficult to set up but if done properly, only trusted applications can send emails. + DKIM signed emails have better delivery rate too.
~Jan Mykhail Hasselbring Web Administrator @ fullstackwebsolution.com