公司使用office 365 e3，最近在做迁移，由于exchange online 暂时迁移排后，所以就准备sharepoint online，在sharepoint online 中可以邀请用户加入站点，简单的功能，但是sharepoint online 管理员说用户无法收到邮件。
最快的方法开case 找微软工程师，和微软工程师一起检查如下项目
1：sharepoint online 邮件发送，其实就是使用exchange online 发送
2：在邮件网关添加sharepoint online ip
IP ADDRESS RANGES | URLS |
|---|---|
42.159.34.0/27 | *.sharepoint.com |
42.159.38.0/23 | *.sharepointonline.com |
42.159.162.0/27 | |
42.159.166.0/23 | |
65.52.45.0/24 | |
65.55.22.32/27 | |
70.37.151.64/27 | |
94.245.113.160/27 | |
104.146.0.0/15 | |
111.221.17.160/27 | |
111.221.20.128/25 | |
111.221.22.32/27 | |
111.221.22.192/27 | |
111.221.64.160/27 | |
111.221.67.0/27 | |
111.221.67.32/27 | |
111.221.67.64/27 | |
111.221.67.96/27 | |
134.170.200.0/23 | |
134.170.202.0/23 | |
134.170.204.0/23 | |
134.170.206.0/23 | |
134.170.208.0/23 | |
134.170.210.0/23 | |
134.170.212.0/23 | |
134.170.214.0/23 | |
134.177.0.0/16 | |
157.55.43.32/27 | |
157.55.46.128/27 | |
157.55.56.0/27 | |
157.55.62.96/27 | |
157.55.62.128/27 | |
157.55.103.0/27 | |
157.55.144.64/27 | |
157.55.144.96/27 | |
157.55.145.192/27 | |
157.55.147.0/27 | |
157.55.152.128/27 | |
157.55.152.160/27 | |
157.55.152.192/27 | |
157.55.152.224/27 | |
157.55.153.0/27 | |
157.55.153.64/27 | |
157.55.153.96/27 | |
157.55.154.64/27 | |
157.55.225.160/27 | |
157.55.225.224/27 | |
157.55.227.128/27 | |
157.55.229.0/27 | |
157.55.229.32/27 | |
157.55.229.64/27 | |
157.55.229.96/27 | |
157.55.229.160/27 | |
157.55.231.32/27 | |
157.55.232.0/27 | |
157.55.235.64/27 | |
157.55.238.128/27 | |
157.56.24.128/27 | |
157.56.48.0/27 | |
157.56.80.128/27 | |
157.56.81.192/27 | |
157.56.81.224/27 | |
157.56.113.0/27 | |
157.56.132.128/27 | |
157.56.132.160/27 | |
157.56.150.32/27 | |
191.232.0.0/23 | |
191.234.8.0/23 | |
191.234.10.0/23 | |
191.234.12.0/23 | |
191.234.14.0/23 | |
191.234.76.0/23 | |
191.234.128.0/21 | |
191.234.144.0/23 | |
191.234.148.0/23 | |
191.234.150.0/23 | |
191.234.152.0/23 | |
191.235.0.0/20 | |
207.46.203.128/27 | |
213.199.179.0/27 | |
2a01:111:f402::/64 | |
2a01:111:f402:a000::/64 | |
2a01:111:f402:a001::/64 | |
2a01:111:f402:a002::/64 | |
2a01:111:f402:a003::/64 | |
2a01:111:f402:a004::/64 | |
2a01:111:f402:a006::/64 | |
2a01:111:f402:a800::/64 | |
2a01:111:f402:a801::/64 | |
2a01:111:f402:a802::/64 | |
2a01:111:f402:a803::/64 | |
2a01:111:f402:a805::/64 | |
2a01:111:f402:b000::/64 | |
2a01:111:f402:c00::/64 | |
2a01:111:f402:c01::/64 | |
2a01:111:f402:1::/64 | |
2a01:111:f402:1c00::/64 | |
2a01:111:f402:180a::/64 | |
2a01:111:f402:180b::/64 | |
2a01:111:f402:180c::/64 | |
2a01:111:f402:340a::/64 | |
2a01:111:f402:340b::/64 | |
2a01:111:f402:340c::/64 | |
2a01:111:f402:400::/64 | |
2a01:111:f402:800::/64 | |
2a01:111:f402:940b::/64 | |
2a01:111:f402:940c::/64 | |
2a01:111:f402:940d::/64 | |
2a01:111:f402:1000::/64 | |
2a01:111:f402:1001::/64 | |
2a01:111:f402:1801::/64 | |
2a01:111:f402:1802::/64 | |
2a01:111:f402:1803::/64 | |
2a01:111:f402:1804::/64 | |
2a01:111:f402:1805::/64 | |
2a01:111:f402:1806::/64 | |
2a01:111:f402:1807::/64 | |
2a01:111:f402:1808::/64 | |
2a01:111:f402:1809::/64 | |
2a01:111:f402:2400::/64 | |
2a01:111:f402:2401::/64 | |
2a01:111:f402:2403::/64 | |
2a01:111:f402:3400::/64 | |
2a01:111:f402:3402::/64 | |
2a01:111:f402:3403::/64 | |
2a01:111:f402:3404::/64 | |
2a01:111:f402:3405::/64 | |
2a01:111:f402:3406::/64 | |
2a01:111:f402:3407::/64 | |
2a01:111:f402:3408::/64 | |
2a01:111:f402:3409::/64 | |
2a01:111:f402:8001::/64 | |
2a01:111:f402:8002::/64 | |
2a01:111:f402:8003::/64 | |
2a01:111:f402:8004::/64 | |
2a01:111:f402:8005::/64 | |
2a01:111:f402:8006::/64 | |
2a01:111:f402:8007::/64 | |
2a01:111:f402:8800::/64 | |
2a01:111:f402:8801::/64 | |
2a01:111:f402:8802::/64 | |
2a01:111:f402:9400::/64 | |
2a01:111:f402:9401::/64 | |
2a01:111:f402:9402::/64 | |
2a01:111:f402:9403::/64 | |
2a01:111:f402:9404::/64 | |
2a01:111:f402:9405::/64 | |
2a01:111:f402:9406::/64 | |
2a01:111:f402:9407::/64 | |
2a01:111:f406:8000::/64 | |
2a01:111:f406:8001::/64 | |
2801:80:1d0:1400::/64 |
3)添加@email.microsoftonline.com到白名单
4）禁用exchange online 的域目的为不适用exchange online
5)在exchange online 和本地exchange track center中还是找不到所发出的邀请的邮件
6）测试使用非公司邮件，例如hotmail ，gmail 都能够收到邮件
7)由于当前所有的测试用户都是基于本地目录同步到azure目录，检查每个测试用户的sharepoint profile中邮件地址都是正确的。
8）开始抓瞎，进行不停得测试，其中更换若干工程师，
9）考虑到目录同步问题，因此建立一个本地用户，分配邮箱，但是并不同步到office 365,发现该用户可以接收到邮件。
因此怀疑尽管没有exchange online，但是由于域名和本地域名一致，所以依旧使用exchange online 来发送邮件，同时exchange online认为此人为exchange online 内部用户，因此就发送了邮件，但是没有任何NDR提示。
生下来就比较容易，在exchange online 建立发送连接器，使用MX 记录寻址到我们邮件网关地址。
本地邮件服务器创建接收连接器。
测试一切正常，因此这个例子证明sharepoint online 依旧使用exchange online 来发送邮件，而不在意该域名是否被exchange online 使用，其实我个人认为是个微软设计上的问题。
希望遇到类似的问题，可以有所参考并有帮助。