On Tuesday,  8 May 2018 at 14:16, Eric Abrahamsen wrote:
> My guess is that outlook is building an index for the web interface that
> isn't available for the IMAP server. Unfortunately you can't do anything
> about that -- when issuing an IMAP SEARCH command, only the server knows
> if a search index is available or not. It's possible that there is an
> index but it's gotten corrupted, but then you'd expect the web interface
> to be slow too. It's more likely that they've done one for the web, but
> neglected IMAP.

This sounds very likely.

> If you have a copy of outlook the MUA on your machine, this link might
> (?) be useful:
>
> https://www.stellarinfo.com/blog/fix-outlook-2016-search-problems/

Thanks.  I don't have Outlook and the web interface does not provide any
links for rebuilding the search index.  I don't think there are search
problems as such, given that the OWA interface is fast.  I think it is
indeed that the imap interface to the server is not properly
supported.  Which is not a surprise.

eric
-- 
Eric S Fraga via Emacs 27.0.50 & org 9.1.6 on Debian buster/sid