Description of problem:
I'm using Evolution 2.32 with evolution-mapi 0.32 to access the company Exchange server for mails. It has been working OK except that it failed to send mails randomly. When it failed to send, I would receive the following error:
Error while Sending message.
ModifyRecipients: MAPI error ecRpcFormat (0x4b6) occurred
So far, I can't figure the pattern to cause the failure. Once it happens, the mail will be stuck in the "outbox" "On this computer". It can't be cleared even after I restart the evolution. I have to manually delete it from "outbox".
BTW, even in this error state, I don't have problem receiving mails.

Version-Release number of selected component (if applicable):
[awang@mars evolution]$ rpm -qa | grep evolution
evolution-data-server-2.32.1-1.fc14.x86_64
evolution-mapi-0.32.1-1.fc14.x86_64
evolution-help-2.32.1-1.fc14.noarch
evolution-2.32.1-1.fc14.x86_64
[awang@mars evolution]$ more /etc/redhat-release 
Fedora release 14 (Laughlin)

How reproducible:
Just keep using Evolution and the problem will happen sooner or later.

Steps to Reproduce:
1. Use the Evolution to send and receive mails.
2. Send or reply mail.
3.
  
Actual results:
outbound mail will be stuck in "outbox" "On this computer". A pop up box with the following error message will be displayed.
Error while Sending message.
ModifyRecipients: MAPI error ecRpcFormat (0x4b6) occurred

Expected results:
The mail will be send.

Additional info: