[dba-Tech] Email Program Again

History: To support my clients that need automation, a couple years ago I
switched to Outlook for myself.  Before I used Express and Thunderbird.  I
had a problem with Thunderbird that I couldn't solve, so that helped push me
into Outlook.  The one feature of Outlook that's better (or was) than the
others is the spell check.  Really superior.
 
Now: Outlook has slowed down to the point where I need to do something about
it.   When it gets the mail, it bogs down the machine to the point where
it's annoying - more than.  There is often a delay of several seconds when
displaying a message in the preview pane or deleting a message. I do have
several thousand emails saved in folders although I clean out pretty
regularly.
 
I am running AVG with email scanner but always have - but I wonder if that
might be causing the delay.  Hate to lose that since email's the primary way
to get your machine infected. 
 
What to do:  I could move back to Thunderbird.  It was pretty good -
probably better now than when I used it before.  Express is fine, too.
Especially if those programs can import the Outlook settings - accounts and
address book (I could leave the old emails behind) Outlook Express was
always good to me.
 
Any ideas on a fix for Outlook or a better alternative?
 
MTIA,
 
Rocky