[powershell] How to switch to another domain and get-aduser

I am on a server under the DomainA. I can use Get-ADUser and it's working fine.

Now there is a trust built between DomainA and DomainB. I would like to switch to DomainB and get all the users that's in OU=New Users, DC=DomainB, DC=com.

I tried these but I get an error.

$FetchDomainB = Get-ADUser -SearchBase "OU=New Users, DC=DomainB, DC=com"

This asks me for Filter and i put in emailadress then it throws an error saying "Supplied distinguished name below to dc=DomainA,dc=net"

Same error is thrown for following code as well.

PS C:\> $test = Get-ADUser -SearchBase "dc=DomainB,dc=com" -filter {EmailAddress -like "*Smith_Karla*"} -Properties EmailAddress

get-aduser -Server "servername" -Identity %username% -Properties *

get-aduser -Server "testdomain.test.net" -Identity testuser -Properties *

These work when you have the username. Also less to type than using the -filter property.

EDIT: Formatting.

best solution TNX to Drew Chapin and all of you too:

I just want to add that if you don't inheritently know the name of a domain controller, you can get the closest one, pass it's hostname to the -Server argument.

$dc = Get-ADDomainController -DomainName example.com -Discover -NextClosestSite

Get-ADUser -Server $dc.HostName[0] `
    -Filter { EmailAddress -Like "*Smith_Karla*" } `
    -Properties EmailAddress

my script:

$dc = Get-ADDomainController -DomainName example.com -Discover -NextClosestSite
 Get-ADUser -Server $dc.HostName[0] ` -Filter { EmailAddress -Like "*Smith_Karla*" } `  -Properties EmailAddress | Export-CSV "C:\Scripts\Email.csv

I just want to add that if you don't inheritently know the name of a domain controller, you can get the closest one, pass it's hostname to the -Server argument.

$dc = Get-ADDomainController -DomainName example.com -Discover -NextClosestSite

Get-ADUser -Server $dc.HostName[0] `
    -Filter { EmailAddress -Like "*Smith_Karla*" } `
    -Properties EmailAddress