Skip to main content

Writing a simple scripted process to download attachmentts in Exchange 2007/ 2010 using the EWS Managed API

Every complicated thing in life is made up of smaller simpler building blocks, when it comes to writing a script (or any code really) the more of these little building blocks you have to figure out the more the process of solving a problem can become bewildering. The Internet generally provides you with lots of half eaten sandwiches of information something someone else has taken a bite out but a lot of the time half done, and as with any code its usefulness declines over time as new and better API's and methods are derived. In this post I'm going to go through a simple scripted process that hopefully covers a few more of these smaller building blocks that you might face when asked to come up with a simple costless solution to perform an automated business function with a script.

So the process im going to look at is one that comes up a lot and that is you have an Email that comes into to certain mailbox every day with a certain subject in my case "Daily Export" this email has an attachment that must be downloaded to a fileserver. After the message is downloaded the email should then be moved into a processed folder which is a subfolder of the inbox of the mailbox and marked as Read.

So first this script will be designed to be run once a day from a scheduled task. First off with this script is we need a few variables that need to be hardcoded with some settings.

$MailboxName = ""

This is the emailaddress of the mailbox the script is going to retrieve the message from

$Subject = "Daily Export"

This is the subject of the Email that has the attachment to process.

$ProcessedFolderPath = "/Inbox/Processed"

This is the Folder path to where the message is going to moved to this is needed for the fuction that will find the FolderID of this folder which is important when you go to move messages with EWS.

$downloadDirectory = "c:\temp\"

This is the folder where attachments will be downloaded to

The next part of this script is the FindTargetFolder function this is a function that takes a folderpath in the format of /FirstLevelFolder/SecondLevelFolder etc and then uses this to find the folderID of the folder when the email once processed will be moved to.

The next part of the script is some standard EWS Managed API Powershell stuff that I've talked about a lot before in this post

Then we come to the search filter which is a little interesting this search filter is doing a bitwise AND which means that all three conditions must be meet for it to return items.

$Sfir = new-object Microsoft.Exchange.WebServices.Data.SearchFilter+IsEqualTo([Microsoft.Exchange.WebServices.Data.EmailMessageSchema]::IsRead, $false)
$Sfsub = new-object Microsoft.Exchange.WebServices.Data.SearchFilter+IsEqualTo([Microsoft.Exchange.WebServices.Data.ItemSchema]::Subject, $Subject)
$Sfha = new-object Microsoft.Exchange.WebServices.Data.SearchFilter+IsEqualTo([Microsoft.Exchange.WebServices.Data.EmailMessageSchema]::HasAttachments, $true)
$sfCollection = new-object Microsoft.Exchange.WebServices.Data.SearchFilter+SearchFilterCollection([Microsoft.Exchange.WebServices.Data.LogicalOperator]::And)

So what this filter does is looks for Emails that are unread, have attachments and have a subject "Daily Export". If all these are true then these items will be returned into the finditems collection which brings us to the next part of the script.

foreach($attach in $miMailItems.Attachments){
$fiFile = new-object System.IO.FileStream(($downloadDirectory + “\” + $attach.Name.ToString()), [System.IO.FileMode]::Create)
$fiFile.Write($attach.Content, 0, $attach.Content.Length)
write-host "Downloaded Attachment : " + (($downloadDirectory + “\” + $attach.Name.ToString()))
$miMailItems.isread = $true

This part of the script loads the messsages and then loops through the attachments and downloads them to the specified path.

$miMailItems.isread = $true

These two lines set the message to read and then updates it.


This last line moves the message to the processed folder.

That's it although generally not really but its as far as this half eaten sandwich is going to go but its pretty easy from here. I've put a download of this script here

Popular posts from this blog

Export calendar Items to a CSV file using EWS and Powershell

Somebody asked about this last week and while I have a lot of EWS scripts that do access the Calendar I didn't have a simple example that just exported a list of the Calendar events with relevant information to a CSV file so here it is. I've talked on this one before in this howto  but when you query the calendar folder using EWS you need to use a CalendarView which will expand any recurring appointments in a calendar. There are some limits when you use a calendarview in that you can only return a maximum of 2 years of appointments at a time and paging will limit the max number of items to 1000 per call. So if you have a calendar with a very large number of appointments you need to break your query into small date time blocks. In this example script I'm just grabbing the next 7 days of appointments if you want to query a longer period you need to adjust the following lines (keeping in mind what I just mentioned) #Define Date to Query $StartDate = (Get-Date) $EndDate

Downloading a shared file from Onedrive for business using Powershell

I thought I'd quickly share this script I came up with to download a file that was shared using One Drive for Business (which is SharePoint under the covers) with Powershell. The following script takes a OneDrive for business URL which would look like This script is pretty simple it uses the SharePoint CSOM (Client side object Model) which it loads in the first line. It uses the URI object to separate the host and relative URL which the CSOM requires and also the SharePointOnlineCredentials object to handle the Office365 SharePoint online authentication. The following script is a function that take the OneDrive URL, Credentials for Office365 and path you want to download the file to and downloads the file. eg to run the script you would use something like ./spdownload.ps1 '

The MailboxConcurrency limit and using Batching in the Microsoft Graph API

If your getting an error such as Application is over its MailboxConcurrency limit while using the Microsoft Graph API this post may help you understand why. Background   The Mailbox  concurrency limit when your using the Graph API is 4 as per . This is evaluated for each app ID and mailbox combination so this means you can have different apps running under the same credentials and the poor behavior of one won't cause the other to be throttled. If you compared that to EWS you could have up to 27 concurrent connections but they are shared across all apps on a first come first served basis. Batching Batching in the Graph API is a way of combining multiple requests into a single HTTP request. Batching in the Exchange Mail API's EWS and MAPI has been around for a long time and its common, for email Apps to process large numbers of smaller items for a variety of reasons.  Batching in the Graph is limited to a m
All sample scripts and source code is provided by for illustrative purposes only. All examples are untested in different environments and therefore, I cannot guarantee or imply reliability, serviceability, or function of these programs.

All code contained herein is provided to you "AS IS" without any warranties of any kind. The implied warranties of non-infringement, merchantability and fitness for a particular purpose are expressly disclaimed.