How to pass a list of domains to EOP antispam (Allowed Domains) by powershell

Question

How to pass a list of domains to EOP antispam (Allowed Domains) by powershell

Marc 631

I am trying to pass a list of domains present in a CSV file (Import-CSV) to "Allowed Domains" in a customised (no default) EOP antispam policy.
You helped me with -IPAllowList unfortunately I was not able to adapt it for the "Allowed Domains" list.
Thanks

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Answer 1

Andy David - MVP 157.8K

You can mimic the examples here:
https://www.pei.com/bulk-import-of-whitelist-or-blacklists-lists-into-o365/

Marc 631 Reputation points

2021-07-19T15:05:20.387+00:00
What is the name I have to use instead of "Whitelist 2" ?

It worked only when I changed "Whitelist 2" with "domain" . In this case " the sender address includes.." policy was created and the domain list was associated to it.

foreach ($content in (get-content “C:\whitelist.csv”)){$temp=(get-transportrule “Whitelist 2”).FromAddressContainsWords;$temp+=$content;set-transportrule “Whitelist 2” -FromAddressContainsWords $temp}
Andy David - MVP 157.8K Reputation points

2021-07-19T15:50:02.453+00:00

"Whitelist 2" is the name of the rule itseld
Marc 631 Reputation points

2021-07-19T17:22:52.147+00:00

I have solve it out.
In the code provided by the link the session dedicated to the "domain" was not update in fact it required "SenderDomainIs" and not "FromAddressContainsWords" as below.

foreach ($content in (get-content C:\whitelist.csv)){$temp=(get-transportrule 'rule name').SenderDomainIs;$temp+=$content;set-transportrule 'role name' -SenderDomainIs $temp}

Answer 2

Andy David - MVP 157.8K

Yikes!
Don't do this. Instead allow domains via a transport rule

https://learn.microsoft.com/en-us/microsoft-365/security/office-365-security/create-safe-sender-lists-in-office-365?view=o365-worldwide#recommended-use-mail-flow-rules

Marc 631 Reputation points

2021-07-19T12:13:03.957+00:00

Hi AndyDavid,

thank you for this important suggestion.

Just double check with you. Is the configuration below appropriate?

new rule> the sender's domain is > [add domains]>set the spam confidence level (SCL) to> 0
Audit this rule=High
SAVE

In this case can we use PowerShell to create a new rule to add a long list of domain?
Andy David - MVP 157.8K Reputation points

2021-07-19T12:16:08.32+00:00

Correct, but you want to ensure these messages pass DMARC: (-1 SCL bypasses anti spam)
See that link I posted above
I would create the rule in EAC then add all the required domains.
Marc 631 Reputation points

2021-07-19T12:48:35.093+00:00

OK, got it.
Once created the rule, is there a way to add domains by a script?

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How to pass a list of domains to EOP antispam (Allowed Domains) by powershell

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