mstehle: The CDOs and CDONTS of Messaging Development : CDOEX

FYI: Glen's Exchange Dev Blog is awesome...

mstehle — Wed, 29 Nov 2006 00:51:00 GMT

If you are an Exchange developer and haven't checked out Glen Scales's blog then you are missing out. Chances are he has written part of your project for you and posted it on his blog. Check out his latest post for a script which generates a report of mailbox size broken down by the age of messages...

KB: 919169, Access Denied or 403 Forbidden When Creating Appointments in WebDAV/CDOEX

mstehle — Wed, 22 Nov 2006 00:00:00 GMT

I saw another case on this issue and remembered that I hadn't put this on my blog yet. If you are getting 403's when trying to create an appointment in another user's calendar using WebDAV or an access denied in CDOEX after installing our Send As hotfix (895949) then check out this article...

919169 You cannot save an appointment to another user's calendar by using CDOEX in Exchange Server 2003 after you apply hotfix 895949
http://support.microsoft.com/default.aspx?scid=kb;EN-US;919169

...You will have to open a support incident to get this hotfix....

Note from the article, "In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question."

...In other words you should not be charged for this case if it is opened solely for the purpose of getting the hotfix, any additional troubleshooting or help may incur a cost...

HOWTO: How To Search mv.string Properties using WebDAV

mstehle — Thu, 20 Apr 2006 07:46:00 GMT

...I have posted a new WebDAV sample for using mv.string properties like Keywords and RRule in WHERE clauses, enjoy...

DAV: How To Search mv.string Properties

FYI: New Sample Code! CDOEX & WebDAV How To Add Recurrence to

mstehle — Fri, 10 Mar 2006 05:16:00 GMT

In an effort to provide samples in a organized and repeatable manner, I have created a format for adding code samples to my blog. The code samples will be added as articles which won't get aggregated here. You can also check the TOC to get links to the new sample section as they come available (right now I just have CDOEX and WebDAV section). I will make posts to advertise the new sample additions so that those of you who subscribe to this feed will get notifications but the code itself will be not be in the post. For example...

After struggling to get this just right for items created in Outlook and OWA, I have samples available that add recurrence to a single appointment using CDOEX and WebDAV...

CDOEX: How To Add Recurrence to a Single Appointment

DAV: How To Add Recurrence to a Single Appointment

...Enjoy

HOWTO: Bind to items from CDO/MAPI using WebDAV

mstehle — Wed, 01 Mar 2006 03:50:00 GMT

Summary

Using PR_URL_COMPNAME to bind to an item in WebDAV from CDO/MAPI involves understanding the encoding rules for the Exchange version where the item is homed. These rules are different and incompatiable between Exchange 2000, Exchange 2000 SP 1, and Exchange 2003. These rules are not documented and often require reverse engineering to properly encode URLs.

Reading proptag 0x670E001E via MAPI on a folder or item will return a value such as…

/-FlatUrlSpace-/ca09cf9efaad754e8a85909b04bb255c-12ee443

...which can be appended to a URL and used to access and item or folder via WebDAV…

http://server/exchange/mailbox/-FlatUrlSpace-/ca09cf9efaad754e8a85909b04bb255c-12ee443

More Information

Flat URLs do not have encoding and escaping rules and will work for folders and items in most every DAV operation with the following exceptions:

- as destination of MOVE or COPY operation
- as a source for a DELETE
- for OWA URL commands, e.g. "?cmd=[foo]"

...You are going to use this property in cases where you are stepping out of CDO 1.21 or MAPI code into WebDAV. The HREF in WebDAV is usually created from the subject that was typed in OL (messages created in OWA typically have a GUID file name). The subject in OL can contain characters that must be encoding for use with DAV similar to URL encoding. Rather than figure out those rules, you can use the Flat URL to get the item. The great thing about the proptag is that it is a direct link between MAPI and WebDAV...

...Enjoy...

OUTBOX: Introduction to Exchange Store Event Sinks Part 2

mstehle — Fri, 20 Jan 2006 00:52:00 GMT

Coming from Exchange 5.5 Event Service Scripts to Exchange Store Event Sinks involves more than just understanding the new events available and the registration process. Exchange 5.5 event scripts are written in VBScript with CDO 1.21 as the API to interact with Exchange data. Store Event Sinks can be written in VBScript, VB6, managed (.NET) code, and C++ they use ExOLEDB with ADO and CDOEX to interact with Exchange data. This is greatly improves scalability and performance but requires a bit of retooling for the developer to be comfortable in their new surrounds. The following information discusses what you need to know about the web store how to interact with data using CDOEX and ExOLEDB.

Exchange Store

One important distinction to make between Exchange 5.5 and Exchange 200x is the storage architecture. This is an important consideration when looking at the new API's available in Exchange 2000 and 2003 because many of the new API's relate to what is called Web Store or stream database that is added to the Exchange storage system. Exchange store event sinks, WebDAV, CDOEX, and ExOLEDB with ADO all work against the web store primarily as opposed to CDO 1.21 and MAPI which work against the ESE database (which was part of Exchange 5.5 as well and is commonly referred to as the MAPI database). We will talk about ExOLEDB and CDOEX mainly because that is what you will use in an Exchange Store Event Sink.

Exchange Storage Architecture

http://www.microsoft.com/technet/prodtechnol/exchange/guides/E2k3TechRef/e82e8de0-803a-4c2b-b012-f73d6a677901.mspx

MSDN Exchange Store Reference

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/e2k3/e2k3/wss_references_wss.asp

CDOEX, ADO, Properties, and Exchange SQL

The web store uses native intermittent content such as MIME which allows access through ExOLEDB with ADO and WebDAV and the use of SQL-like queries to find information. This is quite helpful and a little more intuitive for the database programmer. Each item (folders and messages) in the store can be created, modified, and searched like a row in a database were item properties are columns.

Folders can be used like tables and rows, for example to query the subfolders of a given root folder you would select the URL from all items in the root folder where the item "isFolder" column is "true"...

Select "DAV:href" from scope('shallow traversal of <ROOT FOLDER URL>) Where "DAV:isfolder" = True

The following link provides a description of the SQL predicates supported against the web store.

Exchange Store SQL

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/e2k3/e2k3/_exch2k_sql_web_storage_system_sql.asp

Add just like in a database when you write a query like the one of above you need to know two key pieces of data specific to your store, the table name and the available columns. The table name is pretty easy to identify as it is the folder you what to query from. The column names differ for each item type with some overlap. For example appointment items and contact items have most of the same properties of a basic message but they also have their own unique properties that relate to their functions.

The following link provides a listing of properties available on different items organized by namespace. You will use the full namespace and property name when pulling fields from the Fields collection of a CDOEX object or querying in WebDAV or ADO.

Properties by Namespace

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/e2k3/e2k3/wss_references_nsproperties.asp

The interesting thing about this paradigm is that it is often quite easy for a database developer to walk in and start using ExOLEDB with ADO and WebDAV to execute these kind of queries against Exchange. However, a developer coming from MAPI or CDO 1.21 is usually left looking for the objFolder.Folders collection. ExOLEDB with ADO and WebDAV provide a way to retrieve raw information from the server, they are not an object model. CDOEX provides some interfaces and CoClasses to provide a bit of an object model for interacting with the web store.

MSDN Reference for CDOEX CoClasses, Interfaces, etc.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/e2k3/e2k3/_esdk_reference_cdoex.asp

In event sink development you will typically stay within the interfaces of the CDOEX object you open with the URL passed into the event interface. Especially when working with meetings and contacts note that CDOEX provides a supported way for working with these item types. ExOLEDB with ADO and much of WebDAV offers you raw access to the items in the web store, complex item types like appointments and contacts require CDOEX or special WebDAV commands to ensure that all the appropriate properties are being set to ensure that end user clients display and use the information appropriately.

It is important to understand the limitations of each API and where you should use which. CDOEX and ExOLEDB with ADO should only be used on an Exchange server, specifically they can only be used the Exchange server which hosts the mailboxes or public folders you want to access. WebDAV should be used to remotely access Exchange mailboxes and folders that may not reside on the server it is running on, it can also be executed on a non-Exchange server. All of these technologies are supported with managed (.NET) code, CDO 1.21 and MAPI are NOT supported with managed code.

813349 Support policy for Microsoft Exchange APIs with the .NET Framework applications
http://support.microsoft.com/default.aspx?scid=kb;EN-US;813349

Examples

Exchange Tasks

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/e2k3/e2k3/_e2k3_tasks.asp

This is a great starting place when you are looking to see what you can do with Exchange API's. There are all kinds of great code samples here to allow you to do all kinds of stuff against the store. I have pulled a couple samples out that relate to some common tasks developers do inside event sinks.

Adding an Appointment to the Calendar

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/e2k3/e2k3/_cdo_adding_an_appointment_directly_to_the_calendar.asp

Responding to a Meeting Request

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/e2k3/e2k3/_cdo_responding_to_a_meeting_request.asp

Listing Inbox Contents Using ADO

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/e2k3/e2k3/_cdosys_listing_inbox_contents_using_ado.asp

FYI: Exchange 12 Developer Roadmap...

mstehle — Tue, 06 Dec 2005 03:27:00 GMT

A couple days ago I posted a link to upcoming Outlook Object Model changes and new features, I wanted to go back and note that the Exchange team posted about their developer roadmap as well. This post mentions three new ways of interfacing with Exchange in version 12 that you should be really excited about: web services, agent scripts, and the Monad shell. From what I have seen and heard about E12, I can't help but get excited. The Exchange team has done a great job of listening to the community and delivering product features and enhancements that go a long way towards addressing our wish lists as well as things we never knew to ask for.

...I paid particular attention to the following line about web services in E12, "Our new Web Services will offer remotely-accessible Outlook-compatible business logic for all PIM types." Obviously this sentence is intentionally vague but you should be thinking about a remoteable API that would allow access to Outlook item types like Appointments and Contacts. I don't have specifics on which item types will or will not be supported by the E12 web services, you'll have to keep checking with the Exchange team or my blog to get updates in the coming months.

With the new additions there are things that are being de-emphasized and others that will not be available. Note that WebDAV, CDOEX, and EXOLEDB are the three de-emphasized API's. As they suggest agents will replace CDOEX and EXOLEDB for Exchange server eventing, however Event Sinks will still work against E12.

...It is important to understand the support impact of the word "de-emphasized". From my perspective it means that I will support the use of WebDAV, CDOEX, and EXOLEDB against E12 for entire lifecycle of the product, however the product team will not accept design changes or feature enhancements submitted by me on your behalf regarding these API's. It does mean that these API's will have full break/fix support in which the product team will provide with hotfixes and workarounds. It also means that E13+ will most likely not ship support for these API's.

For every new day there is one that has drawn to a close and with that in mind there are a couple existing API's and developer features not continuing to E12. They are listed in the blog post as well. The most common technologies listed here are Web Forms (custom ASP forms in OWA, much like custom forms in Outlook) and CDOWF (Workflow for Exchange apparently will not be supported in E12). The other technologies are less common but I don't doubt that this will impact many of you.

...Most of the technologies listed here that are going away in E12 will have a much better alternative or had some supportability issues to begin with. For example, ExWin32 or the M: drive, isn't considered an API or development technology at all, we don't support doing any development against it in the current versions of Exchange. Web Forms in OWA are almost always better handled through a custom web application or Sharepoint. Workflow application in Exchange can be better served through BizTalk or the new Windows Workflow Foundation...

FYI: Supportability of Exchange API's in Managed Code

mstehle — Tue, 22 Nov 2005 23:21:00 GMT

As more and more developers move to managed code (.NET), especially with the release of Visual Studio 2005, it is important to be reminded of what current API's are supported for use in managed code and which are not. The following KB article is a must read when starting .NET development against Exchange, Outlook, or SMTP.

http://support.microsoft.com/default.aspx?scid=kb;en-us;813349

...We all would like to see more supportability with .NET from our Exchange API's. Exchange 12 could offer some more options to that end. It is important to know the basics about all our API's, their functionality limitations, and supportability concerns. Exchange development often requires blending multiple API's to get the job done; you should be open to that possibility.