When sending mail, POSTDROP:WARNING:INET_PROTOCOLS:IPV6 support was disabled:address family not supported by

Linux6.5 when sending a message, the exception postdrop:warning:inet_protocols:IPv6 support was disabled:address family not supported by

Error message:

SENDMAIL:WARNING:INET_PROTOCOLS:IPV6 support was disabled:address family not supported by protocol
APP 12838 stdout:sendmail:warning:inet_protocols:configuring for IPV4
APP 12838 stdout:postdrop:warning:inet_protocols:IPv6 Support was disabled:address family not supported by protocol
APP 12838 stdout:postdrop:warning:inet_protocols:configuring for IPV4
APP 12838 stdout:postdrop:warning:unable to look up public/pickup:no such file or directory
APP 12731 stderr:rendered mails/mail_successed.html.erb within layouts/mails (0.5MS)
APP 12731 stderr:rendered common/_top.html.erb (1.5ms)
APP 12731 stderr:rendered common/_mail_manage.html.erb (0.9ms)
APP 12731 stderr:rendered common/_footer.html.erb (0.1ms)

Workaround:

(1) Modify #/ETC/POSTFIX/MAIN.CF This file
(2) Modify the content: Change inet_protocols = all to Inet_protocols = IPv4
(3) Deposit and withdrawal wq!
(4) Reboot #/etc/init.d/postfix Restart make the changes take effect
(5) OK

Reference article: http://blog.hexu.org/archives/1702.shtml

When sending mail, POSTDROP:WARNING:INET_PROTOCOLS:IPV6 support was disabled:address family not supported by