企业邮箱给谷歌报错550-5.7.25解决方案

This is the mail system at host mail.XXXXX.cn.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
                   The mail system
<XXXXXXXXXXX@gmail.com>: host alt1.gmail-smtp-in.l.google.com[173.194.65.27]
    said: 550-5.7.25 [XXX.XXX.XXX.XXX] The IP address sending this message does
    not have a 550-5.7.25 PTR record setup, or the corresponding forward DNS
    entry does not 550-5.7.25 point to the sending IP. As a policy, Gmail does
    not accept messages 550-5.7.25 from IPs with missing PTR records. For more
    information, go to 550-5.7.25
    https://support.google.com/mail/answer/81126#ip-practices  550-5.7.25 To
    learn more about Gmail's sender policy, go to 550 5.7.25
    https://support.google.com/mail/answer/81126.
    z64-20020a633343000000b005f0a5246e88si5915463pgz.392 - gsmtp (in reply to
    end of DATA command)

1.发送此邮件的 IP 地址没有 PTR 记录设置，或者对应的正向 DNS 条目没有指向发件人 IP。根据政策规定，Gmail 不接受从缺少 PTR 记录的 IP 发出的邮件。有关详情，请参阅电子邮件发件人指南。
​
2.发件人 IP 与指针 (PTR) 记录中指定的主机名的 IP 地址不一致。有关详情，请参阅电子邮件发件人指南。
​

公网IP： XXX.XXX.XXX.XXX 
作用自建企业邮箱
1. 我司内部邮箱 xx@XXXX.com邮箱 给国内的163和新浪和企业内部发送邮件可以成功
2. 给Hotmail发送邮件，成功
3. 给Gmail发送邮件，报错！
​
谷歌Gmail报错：550 5.7.25
1.发送此邮件的 IP 地址没有 PTR 记录设置，或者对应的正向 DNS 条目没有指向发件人 IP。根据政策规定，Gmail 不接受从缺少 PTR 记录的 IP 发出的邮件。
2.发件人 IP 与指针 (PTR) 记录中指定的主机名的 IP 地址不一致。

# yum install bind-utils -y
​
# nslookup -qa=ptr <IP地址-XXX.XXX.XXX.XXX>
*** Invalid option: qa=ptr
XXX.XXX.XXX.XXX.in-addr.arpa     name = mail.XXXX.cn.
Authoritative answers can be found from: