AppointmentItem.ItemProperty + Exchange-Cache-Mode

Question

Hello,

i want save some additional data in an Appointment.

I am using the command AppointmentItem.ItemProperty.Add and save some Text.

2 Questions:

1. Are there a limit of space (e.g.1MB data). I need to save huge amount of data

2. Are the ItemProperties synchronized within Exchange-Cache-Mode? I need to know if ist possible that the .ost-file increases a lot. Otherwise I need the data in a really fast way.

Answer 1

Hello Andreas,

1. Please take a look at the similar forum thread max Length for userProperty Value. . Internally, text properties are stored as an array of bytes. So, it can be any size. But if you develop a .Net based add-in you will be limited with the string type length. See What is the maximum possible length of a .NET string? for details.

2. All data is synchronized with the Exchange server. But the cached mode allows you to store data locally and work offline and use slow connections. The Choose between Cached Exchange Mode and Online Mode for Outlook 2013 article describes both modes in depth. It states:

If users work with a very large mailbox, you can reduce the size of the local data file by using Cached Exchange Mode with the Exchange Fast Access Sync Slider enabled. Sync Slider lets Outlook 2013 users limit the email messages that are synchronized locally in their Outlook data file (.ost). By default, if Cached Exchange Mode is enabled, Outlook 2013 will cache email messages only from the last 12 months and remove anything older than 12 months from the local cache. The email messages that are removed from the local cache are still available for users to view, but they’ll need to be connected to the Exchange Server computer to view them.

Answer 2

Thank you for your reply.

I already tried to save a UserProperty with a size of approx. 30MB to an appointment. It was no problem at all.I expected that the ost-file increases at the same size (minus compression benefit). But the size didn't changed at all.

Are only mails included in the ost-file? Your arcticle sounds like that.

Are the appoinemts cached as well? Where?

Answer 3

I found another article:

http://office.microsoft.com/en-us/outlook-help/introduction-to-outlook-data-files-pst-and-ost-HA010354876.aspx

Appointments are also included, but are the UserProperty cached as well?

Or is Outlook asking the Exchange-Server to get the property?

Answer 4

Andreas,

I'd recommend asking such questions in the Exchange server related forum instead: Exchange Server Development .

Answer 5

If there was an empty blob of that size or larger inside the OST file, the file size would not increase at all.

All item properties are stored in the OST file.

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Dmitry Streblechenko (MVP)
http://www.dimastr.com/redemption Redemption - what the Outlook Object Model should have been Version 5.5 is now available!