Script to Import SMTP Aliases and X500 into Exchange Online

ImportSMTP.ps1

<# ------------------------------------------------------------
 Import_Primary_SMTP_X500_AddMissingOnly_WithStatusCsv.ps1

 Reads:  Identity,Type,Value
 Writes: Identity,Type,Value,Status,Message,Timestamp

 ADD MISSING ONLY:
   - SMTP (Type=SMTP) -> adds secondary proxy (forces smtp:)
   - X500 (Type=X500) -> adds x500:
   - PrimarySMTP (Type=PrimarySMTP) -> optionally sets primary (controlled by $ApplyPrimarySMTP)

 Hard-coded paths.
 Supports -WhatIf/-Confirm via ShouldProcess.
------------------------------------------------------------- #>

[CmdletBinding(SupportsShouldProcess = $true, ConfirmImpact = 'Medium')]
param()

# ----------------------------
# Hard-coded settings
# ----------------------------
$InputCsv         = "C:\Data\TestImport.csv"
$StatusCsv         = "C:\Data\Import_Log_{0}.csv" -f (Get-Date -Format "yyyyMMdd_HHmmss")

# If you want to ALSO apply PrimarySMTP rows (this changes primary, but does NOT remove aliases),
# set this to $true. If you only want to restore SMTP aliases + X500, set to $false.
$ApplyPrimarySMTP  = $true

# If your CSV is semicolon-delimited, set this to ';' otherwise ','
$Delimiter         = ','

# ----------------------------
# Helpers
# ----------------------------
function New-StatusRow {
    param(
        [string]$Identity,
        [string]$Type,
        [string]$Value,
        [string]$Status,
        [string]$Message
    )
    [pscustomobject]@{
        Identity  = $Identity
        Type      = $Type
        Value     = $Value
        Status    = $Status
        Message   = $Message
        Timestamp = (Get-Date -Format "yyyy-MM-dd HH:mm:ss")
    }
}

function Normalize-PrimaryEmail {
    param([string]$Value)
    if ([string]::IsNullOrWhiteSpace($Value)) { return $null }
    $v = $Value.Trim()
    if ($v -match '^(?i)smtp:') { $v = $v.Substring(5) }
    return $v.Trim()
}

function Normalize-SmtpProxy {
    param([string]$Value)
    if ([string]::IsNullOrWhiteSpace($Value)) { return $null }
    $v = $Value.Trim()

    # Add prefix if missing
    if ($v -notmatch '^(?i)smtp:') { $v = "smtp:$v" }

    # Force lowercase prefix to prevent accidental "primary"
    return ("smtp:" + $v.Substring(5)).Trim()
}

function Normalize-X500Proxy {
    param([string]$Value)
    if ([string]::IsNullOrWhiteSpace($Value)) { return $null }
    $v = $Value.Trim()

    if ($v -notmatch '^(?i)x500:') { $v = "x500:$v" }
    return ("x500:" + $v.Substring(5)).Trim()
}

# ----------------------------
# Start
# ----------------------------
Write-Host "Importing from: $InputCsv" -ForegroundColor Cyan
Write-Host "Writing status CSV: $StatusCsv" -ForegroundColor Cyan
Write-Host "Apply PrimarySMTP rows: $ApplyPrimarySMTP" -ForegroundColor Cyan

if (-not (Test-Path $InputCsv)) { throw "Input CSV not found: $InputCsv" }

# Import input
$rows = Import-Csv -Path $InputCsv -Delimiter $Delimiter
if (-not $rows -or $rows.Count -eq 0) { throw "No rows found in CSV: $InputCsv" }

# Validate required columns exist
$cols = $rows[0].PSObject.Properties.Name
foreach ($req in @("Identity","Type","Value")) {
    if ($cols -notcontains $req) {
        throw "CSV must contain columns: Identity, Type, Value. Missing: $req. Found: $($cols -join ', ')"
    }
}

# Status rows accumulator
$statusOut = New-Object System.Collections.Generic.List[object]

# Cache per mailbox to avoid repeated Get-Mailbox calls
# Key: Identity -> HashSet of proxy strings (case-insensitive)
$proxyCache = @{}

foreach ($r in $rows) {

    $identity = ([string]$r.Identity).Trim()
    $type     = ([string]$r.Type).Trim()
    $value    = [string]$r.Value  # may be null

    # Basic validation per row (and still write to status CSV)
    if ([string]::IsNullOrWhiteSpace($identity)) {
        $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $value -Status "SkippedBlank" -Message "Blank Identity"))
        continue
    }
    if ([string]::IsNullOrWhiteSpace($type)) {
        $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $value -Status "SkippedBlank" -Message "Blank Type"))
        continue
    }
    if ($type -match '^(?i)error|none$') {
        $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $value -Status "Skipped" -Message "Non-actionable Type"))
        continue
    }

    try {
        # Prime cache if needed
        if (-not $proxyCache.ContainsKey($identity)) {
            $mbx = Get-Mailbox -Identity $identity -ErrorAction Stop
            $set = New-Object 'System.Collections.Generic.HashSet[string]' ([System.StringComparer]::OrdinalIgnoreCase)
            foreach ($p in ($mbx.EmailAddresses | ForEach-Object { $_.ToString() })) {
                [void]$set.Add($p)
            }
            $proxyCache[$identity] = $set
        }

        switch -Regex ($type) {

            '^(?i)PrimarySMTP$' {
                if (-not $ApplyPrimarySMTP) {
                    $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $value -Status "Skipped" -Message "ApplyPrimarySMTP disabled"))
                    break
                }

                $primaryEmail = Normalize-PrimaryEmail -Value $value
                if ([string]::IsNullOrWhiteSpace($primaryEmail)) {
                    $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $value -Status "SkippedBlank" -Message "Blank PrimarySMTP value"))
                    break
                }

                if ($PSCmdlet.ShouldProcess($identity, "Set Primary SMTP to '$primaryEmail'")) {
                    try {
                        Set-Mailbox -Identity $identity -PrimarySmtpAddress $primaryEmail -ErrorAction Stop
                        $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $primaryEmail -Status "Updated" -Message "Primary SMTP set"))
                    }
                    catch {
                        # fallback
                        Set-Mailbox -Identity $identity -WindowsEmailAddress $primaryEmail -ErrorAction Stop
                        $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $primaryEmail -Status "Updated" -Message "Primary SMTP set (WindowsEmailAddress fallback)"))
                    }

                    # Refresh cache after primary change
                    $mbx2 = Get-Mailbox -Identity $identity -ErrorAction Stop
                    $newSet = New-Object 'System.Collections.Generic.HashSet[string]' ([System.StringComparer]::OrdinalIgnoreCase)
                    foreach ($p in ($mbx2.EmailAddresses | ForEach-Object { $_.ToString() })) {
                        [void]$newSet.Add($p)
                    }
                    $proxyCache[$identity] = $newSet
                }
                else {
                    $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $primaryEmail -Status "WhatIf" -Message "Would set Primary SMTP"))
                }
                break
            }

            '^(?i)SMTP$' {
                $smtpProxy = Normalize-SmtpProxy -Value $value
                if ([string]::IsNullOrWhiteSpace($smtpProxy)) {
                    $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $value -Status "SkippedBlank" -Message "Blank SMTP value"))
                    break
                }

                if ($proxyCache[$identity].Contains($smtpProxy)) {
                    $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $smtpProxy -Status "SkippedAlreadyPresent" -Message "SMTP proxy already exists"))
                    break
                }

                if ($PSCmdlet.ShouldProcess($identity, "Add SMTP proxy '$smtpProxy'")) {
                    Set-Mailbox -Identity $identity -EmailAddresses @{Add = $smtpProxy} -ErrorAction Stop
                    [void]$proxyCache[$identity].Add($smtpProxy)
                    $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $smtpProxy -Status "Added" -Message "SMTP proxy added"))
                }
                else {
                    $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $smtpProxy -Status "WhatIf" -Message "Would add SMTP proxy"))
                }
                break
            }

            '^(?i)X500$' {
                $x500Proxy = Normalize-X500Proxy -Value $value
                if ([string]::IsNullOrWhiteSpace($x500Proxy)) {
                    $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $value -Status "SkippedBlank" -Message "Blank X500 value"))
                    break
                }

                if ($proxyCache[$identity].Contains($x500Proxy)) {
                    $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $x500Proxy -Status "SkippedAlreadyPresent" -Message "X500 proxy already exists"))
                    break
                }

                if ($PSCmdlet.ShouldProcess($identity, "Add X500 proxy '$x500Proxy'")) {
                    Set-Mailbox -Identity $identity -EmailAddresses @{Add = $x500Proxy} -ErrorAction Stop
                    [void]$proxyCache[$identity].Add($x500Proxy)
                    $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $x500Proxy -Status "Added" -Message "X500 proxy added"))
                }
                else {
                    $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $x500Proxy -Status "WhatIf" -Message "Would add X500 proxy"))
                }
                break
            }

            default {
                $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $value -Status "SkippedUnknownType" -Message "Unknown Type value"))
                break
            }
        }
    }
    catch {
        $statusOut.Add((New-StatusRow -Identity $identity -Type $type -Value $value -Status "Error" -Message $_.Exception.Message))
        continue
    }
}

# Export status CSV (same shape as import, plus status columns)
$statusOut | Export-Csv -Path $StatusCsv -NoTypeInformation -Encoding UTF8
Write-Host "Import finished. Status written to: $StatusCsv" -ForegroundColor Green