Hello,
As my mail server is checking the sender host name against the IP address, your mails are rejected since your infrastructure change.
reject: RCPT from unknown[184.94.240.100]: 450 4.7.25 Client host rejected: cannot find your hostname, [184.94.240.100] proto=ESMTP helo=<vmx.spamcop.net>
The reason is a wrong DNS setup. Forward lookup of vmx.spamcop.net. must return 184.94.240.100. instead of 184.94.240.112
Reverse lookup is right.
dig vmx.spamcop.net
;; ANSWER SECTION:
vmx.spamcop.net. 300 IN A 184.94.240.112
dig -x 184.94.240.100
;; ANSWER SECTION:
100.240.94.184.in-addr.arpa. 60 IN PTR vmx.spamcop.net.
