Append string to variable in each iteration of for loop in Powershell.

Question

Thanks so much I was able to get it working with the following command!
PowershellGet-Mailbox | where {$_.Name -eq "admin"} | foreach-object {Set-Mailbox -Identity $_.Name -DisplayName "$($_.DisplayName) ABBREVIATION"}
As for their reasoning behind wanting multiple mailboxes, they seem to be wanting to operate as 2 separate entities still. So their old clients still work with them under the old company name and they are paranoid about having names crossover mistakenly. We did try to get them to switch over to 1 mailbox and demonstrated it for them, but this is what they requested.

Answer 1

I have to ask - why keep two separate mailboxes for each user rather than just have one mailbox with multiple addresses?But yes, you can concatenate just like other languages. You have two problems currently -
1. You aren't referencing anything with "$.DisplayName". You need to use "$_.DisplayName" and you need to use it in a Foreach-Object script block.2. You need to pass the concatenated string as a single argument to the -DisplayName parameter. There are several ways to do this but the problem you're having is because there is whitespace in your argument.
PowershellGet-Mailbox | where {$_.Name -eq "admin"} | foreach-object {Set-Mailbox -DisplayName ($_.DisplayName + ' ABBREVIATION')}#ORGet-Mailbox | where {$_.Name -eq "admin"} | foreach-object {Set-Mailbox -DisplayName "$($_.DisplayName)ABBREVIATION"}