I write to tell you our problem :
since we have activated our internal mail server , our public ip ( 5.xxx.xx.xx *) is blocked by the symantec black-list
Reason: The host has been Observed sending spam in a format that is similar to snow shoe spamming techniques.The host is unauthorized to send email Directly to email servers).
We have configured everything correctly :
record ptr, spf , dkim,dmarc
Our ip is not included in any black-list, we have problems sending mail only to the domain “istruzione.it” which uses the symantec black-list.
In the span of 10 days we had to request the delisting 3 times, today we are stuck again.
I can provide our public Ip in a private message
It is possible to have a contact to solve this problem ?
Thank you for your cooperation