My ISP providesa fixed IPv4 IP address and allocates random IPv6 IP addresses drawn from a pool of 64. This is causing problems with emails bouncing when sent to Gmail addresses. Gmail regards the random IPv6 addresses as not authenticated to the server. This is a new problem after recently changing ISP. The advice from the new ISP is to turn off IPv6 in the email server at least in the short term. We have a large email campaign due out tomorrow so I'm looking for a short-term fix and how best to manage things properly in the longer term to use IPv6. I welcome your advice.
Settings postfix to ipv4 only should be fine. In postfix main.cf file, set or change the line: Code: inet_protocols = ipv4 and restart postfix.
