?
Solved

Receive connector to only accept mail from Office 365

Posted on 2016-11-22
3
Medium Priority
?
235 Views
Last Modified: 2017-01-17
Hello Experts,

I have a non-profit customer that I'm currently setting up a hybrid configuration for. We recently got them set up with a new server with Exchange 2016. They used Office 365 for their second location that is now combined with the first and on their local domain. During the first part of the migration I changed over their MX records to look directly at their external IP for a standard configuration, but the amount of spam they were getting was ridiculous.  So, last night I changed their MX record to look to Office 365 (they don't mind still paying their minuscule non-profit pricing for O365 just for the spam filtering) and configured the connectors on O365 to forward the mail onto the on-prem server. That all works fine, but they are still receiving a large amount of spam. I'm not seeing any of those messages being passed through O365, so i'm assuming it's all being sent to their outside IP address and the Exchange server is still delivering them. My question is how do I set up the receive connector so that it only accepts outside mail from O365. I've set up internal spam filters before where you just have it only accept mail from a single IP, but Microsoft has so many IPs, it doesn't look like I can do that. Any suggestions would be great!

Best,
Taylor
0
Comment
Question by:Taylor
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
3 Comments
 
LVL 20

Accepted Solution

by:
Peter Hutchison earned 1400 total points
ID: 41899121
Yes, the only way to do it is to configure your receive connectors with a list of IPs.
addresses or IP address ranges on the network settings of the receive connector. Microsoft have published a complete list here:

Exchange Online Protection IP addresses:
https://technet.microsoft.com/en-us/library/dn163583(v=exchg.150).aspx
2
 
LVL 37

Assisted Solution

by:Jian An Lim
Jian An Lim earned 600 total points
ID: 41899864
OR logon to exchange online and run the following command

Get-HybridMailflowDatacenterIPs | select DatacenterIPs

then you can use this to put on your receive connector easily
1
 

Author Comment

by:Taylor
ID: 41899871
Great! Thanks guys. I'll give this a try and let you know. Sorry I didn't respond sooner Peter, I never received a notification for you comment.
0

Featured Post

Concerto Cloud for Software Providers & ISVs

Can Concerto Cloud Services help you focus on evolving your application offerings, while delivering the best cloud experience to your customers? From DevOps to revenue models and customer support, the answer is yes!

Learn how Concerto can help you.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

There are times when we need to generate a report on the inbox rules, where users have set up forwarding externally in their mailbox. In this article, I will be sharing a script I wrote to generate the report in CSV format.
A couple of months ago we ran into an issue that necessitated re-creating our Edge Subscriptions. However, when we attempted to execute the command: New-EdgeSubscription -filename C:\NewEdgeSub_01.xml we received an error indicating that the LDAP se…
how to add IIS SMTP to handle application/Scanner relays into office 365.
Visualize your data even better in Access queries. Given a date and a value, this lesson shows how to compare that value with the previous value, calculate the difference, and display a circle if the value is the same, an up triangle if it increased…

719 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question