EWS open another mailbox - powershell

Question

how can I open another mailbox via EWS? I have full access to the mailbox.
With the code I can open my personal mailbox.
$service = New-Object Microsoft.Exchange.WebServices.Data.ExchangeService
$service.Credentials = New-Object System.Net.NetworkCredential -ArgumentList
$mail, $password
$service.URL = New-Object Uri("outlook.office365.com/EWS/Exchange.asmx")
# Set how many emails we want to read at a time
$numOfEmailsToRead = 5
# Index to keep track of where we are up to. Set to 0 initially.
$index = 0
# Do/while loop for paging through the folder
do {
# Set what we want to retrieve from the folder. This will grab the first $pagesize emails
$view = New-Object Microsoft.Exchange.WebServices.Data.ItemView($numOfEmailsToRead, $index)
# Retrieve the data from the folder
$findResults = $service.FindItems([Microsoft.Exchange.WebServices.Data.WellKnownFolderName]::Inbox, $view)
foreach ($item in $findResults.Items) {
# load the additional properties for the item
$item.Load($propertySet)
# Output the results
$msgProperty = New-Object Microsoft.Exchange.WebServices.Data.PropertySet([Microsoft.Exchange.WebServices.Data.EmailMessageSchema]::MimeContent)
$email = [Microsoft.Exchange.WebServices.Data.EmailMessage]::Bind($service, $item.Id, $msgProperty)
...
} while ($findResults.MoreAvailable)
thank you for your support

Answer 1

You need to use the Mailbox overload for the folderid object so change
$findResults = $service.FindItems([Microsoft.Exchange.WebServices.Data.WellKnownFolderName]::Inbox, $view)
To something like
$MailboxName = "blah#blah.com"
$folderid = new-object Microsoft.Exchange.WebServices.Data.FolderId([Microsoft.Exchange.WebServices.Data.WellKnownFolderName]::Inbox, $MailboxName)
$findResults = $service.FindItems($folderid , $view)