Function that'll connect to either on premise Exchange or Office 365 Exchange

Connect-Exchange.ps1

#Requires -Version 4.0
#Requires -modules ActiveDirectory
function Connect-Exchange {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true,
            HelpMessage="User admin credentials")]
        [System.Management.Automation.PSCredential]$Credential,
        [Parameter(Mandatory=$false)]
        $URI = "https://outlook.office365.com/powershell-liveid/",
        [Parameter(Mandatory=$false)]
        [Bool]$Online=$false,
        [Parameter(Mandatory=$false)]
        [String]$Prefix = ""
    )
    if($Online) { #Office 365
        $ExchangeOptions = @{
            ConfigurationName = "Microsoft.Exchange"
            ConnectionUri = $URI
            Authentication = "Basic"
            Credential = $Credential
        }
        $ExcName = "Office 365"
        $ExcFound = $true
    }
    else { #On premise
        $ExcServerList = Get-ADGroupMember -Identity "Exchange Servers" | Where-Object {$_.objectClass -eq "computer"}
        if($ExcServerList -is [Array]) {
            Format-Displaylist -ArrayList $ExcServerList -DisplayName
            $ServerSelect = Get-UserInput -DisplayText "Select the Exchange server you want to connect to" -intSearch -boundSearch $ExcServerList.Count
            $ExcServer = $ExcServerList[$ServerSelect - 1]
            $ExcFound = $true
        }
        elseif($ExcServerList -ne $null) {
            $ExcServer = $ExcServerList
            $ExcFound = $true
        }
        else {
            $ExcFound = $false
        }
        if($ExcFound) {
            $ExcName = $ExcServer.Name
            $ExchangeOptions = @{
                ConfigurationName = "Microsoft.Exchange"
                ConnectionUri = "http://$ExcName/PowerShell"
                Authentication = "Kerberos"
                Credential = $Credential
            }
        }
    }
    if($ExcFound) {
        Write-Host "Connecting to $ExcName..." -NoNewline
        $Session = New-PSSession @ExchangeOptions
        $PSSessionOptions = @{
            Session = $Session
            DisableNameChecking = $true
            AllowClobber = $true
        }
        $ModuleOptions = @{
            Global = $true
            DisableNameChecking = $true
        }
        if($Prefix -ne "") {
            $ModuleOptions.Add("Prefix",$Prefix)
        }
        Import-Module (Import-PSSession @PSSessionOptions) @ModuleOptions | Out-Null
        Write-Host "done."
    }
    else {
        Write-Host "Could not find an Exchange server on the domain. Exiting."
    }
}