Created attachment 142241 [details]
backtrace while updating 

Every 5 minutes my CPU and network go through the roof as my "check for new
mail every 5 minutes" fires.
I then get:
Retrieving message IDs from server for Inbox
Along with to STDERR:
exchange-mapi-connection.c:2304: Entering exchange_mapi_set_flags
libexchangemapi-Message: exchange-mapi-connection.c:2306:
exchange_mapi_set_flags: lock(connect_lock)
libexchangemapi-Message: exchange-mapi-connection.c:2344:
exchange_mapi_set_flags: unlock(connect_lock)
exchange-mapi-connection.c:2346: Leaving exchange_mapi_set_flags 
exchange-mapi-connection.c:1091: Entering exchange_mapi_connection_fetch_items:
folder-id 4DDDEC0800000003 libexchangemapi-Message:
exchange-mapi-connection.c:1093: exchange_mapi_connection_fetch_items:
lock(connect_lock)
libexchangemapi-Message: exchange-mapi-connection.c:1314:
exchange_mapi_connection_fetch_items: unlock(connect_lock)
exchange-mapi-connection.c:1316: Leaving exchange_mapi_connection_fetch_items:
folder-id 4DDDEC0800000003 
exchange-mapi-connection.c:1091: Entering exchange_mapi_connection_fetch_items:
folder-id 4DDDEC0800000003 libexchangemapi-Message:
exchange-mapi-connection.c:1093: exchange_mapi_connection_fetch_items:
lock(connect_lock)
libexchangemapi-Message: exchange-mapi-connection.c:1314:
exchange_mapi_connection_fetch_items: unlock(connect_lock)
exchange-mapi-connection.c:1316: Leaving exchange_mapi_connection_fetch_items:
folder-id 4DDDEC0800000003 

while slowly crawling through the IDs.

This is repeated if I click on any folder.
So if I click on Inbox (indexes Inbox), click on Trash (indexes trash), click
on Inbox again (reindexes Inbox).

I'm using evolution-mapi-0.27.91 against evolution 2.27.91.

This behaviour did not happen in 0.26, however 0.26 has many more problems with
it so I'm just putting up with this behaviour. Downgrading isn't really
practical.

At mcrha's request I generated the following:
gdb --batch --ex "t a a bt" -pid=4975 &>bt.log

Which is attached.