Outlook 2000 running very slow with our COM add-in enabled

[yinjennytam]

Hi, we have released our COM add-in for more than a year and this add-in
supports Outlook 2000, 2002 and 2003. So far we have customers using
different versions of Outlook and recently a new customer has a strange
problem that we haven't heard of.

The problem is that once they have installed our add-in, Outlook 2000
becomes very slow (sometimes up to 5 times slower) to open or close email
windows. As soon as they disable our add-in, Outlook 2000 is back to normal.
We have recommended that they upgrade to Outlook 2000 SP3, but even with
that the problem still exists. They connect to Exchange Server 2000.

We haven't been able to reproduce this performance difference on our side
and we haven't had any customer complaining that as well. Therefore, we
suspect it's something in their environment. However, they claim that all
their 40 users have the same problem. So it's not just one or two users.

Do you have any clue why this could happen? Any feedback or comments are
appreciated! Thank you very much!

 

[Dmitry Streblechenko]

What does your add-in do when a message is opened?

Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool

 

[yinjennytam]

Thank you for your quick response.

Actually a few things. I will summarize them here:

(1) Check if the email is opened from a special folder
(2) Check if it contains some custom MAPI properties, and if so, we will
unserialize it to get our object
(3) Check if Word editor is used or not and do something special
(4) Add our custom CommandBar if not found in the Inspector and add some
buttons and combos to it

The main difference for Outlook 2000 is in step (4), which we need to save
the clipboard contents before adding button bitmaps and restore the clipboard
afterwards.

Otherwise, the rest is the same for our implementation in Outlook 2000, 2002
and 2003. So far only the customer experience the major performance
difference with our add-in enabled. As I said earlier, once it is not
loaded, Outlook 2000 is back to normal. Unfortunately, so far we cannot
reproduce this on our side.

Does it have anything to do with Exchange Server?

 

[yinjennytam]

Ok found the problem. I have asked the client to try the following:

"Look for the following files (extend.dat, frmcache.dat, outcmd.dat, and
views.dat). Back them up somewhere first then delete them and open Outlook
again and see if it makes any difference. This is known problem prior to
Outlook 2000 SP2."

They did that and it fixed the problem! Hurray!

What are these files doing actually? Now they have upgraded to Outlook 2000
SP3 I don't think this problem will re-occur correct?

Jenny

 

[Dmitry Streblechenko]

extend.dat - cache of installed Exchange Client Extensions (ECE)
frmcache.dat - custom forms
outcmd.dat - toolbar customizations

Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool