Not sure if this is the proper place to post this, and it is a pretty obscure issue for most people here. But perhaps some people will Google this issue and find this
With the 2.3 upgrade there were some changes in the Calendar functions. While on the surface it may seem good, if you are using SyncJe to sync you Calendar via SyncML with, say, Oracle Collaboration Suite a full (read: slow) sync may (most likely will) force everyone on every meeting you have to be e-mailed with a meeting request again.
For reoccurring meetings, everyone will get an e-mail for every instance of the meeting (good fun). Needless to say, this can and will cause quite a bit of e-mail to be sent out.
Even when you delete a Calendar item and specifically say "No" to sending an e-mail to other invitees of it being canceled it will still send them.
Not sure how much this is just a BIS 2.3 specific issue and it happens in general, or if the combination of BIS 2.3 and SyncJe causes this.
Solution is simple:
Delete the CICAL service books for your personal e-mail addresses and reboot. This will allow syncing to resume normally and not flood the world with e-mail calendar notifications.
The down side is you cannot "invite" attendees to meeting you add in your BlackBerry anymore.
Not sure whatever side effects are to be found with the removing of the service books. Will know more when I have some people send me some Calendar invites in the morning.
And before anyone asks, it's no fun when you have a great BES setup working for years with no problems and then you get acquired by, you guess it, Oracle and are forced to use Oracle Collaboration Suite (which there is no BES connector for)!
Mods: if this is in the wrong place please feel free to move.