Currently it is only possible to us the "Group"  Template (which allows for
gathering multiple sender addresses to be added to the filter conditions) via
the filter assistant and then moving the emails. It would be good to support
this with the message command "quickFilters: create filter from message".

If more than one email is selected the message "To create a filter, please
select exactly one email!" is shown.

Currently the only workaround is to add the recipients one by one and using the
merge feature.

This is just a comment to get me added

Created an attachment (id=7812) [details]
2.5 prerelease 6

Here is a patched version - note that you  must select the "Group" template in
order to harvest email addresses from multiple emails. Note that the "Group"
template goes through the email addresses listed in your mail accounts
(identities) and removes them from the list (as it is not useful to filter
mails sent by yourself).

Created an attachment (id=7818) [details]
2.5 prerelease 33

Added the expansion of most address fields and also made it resilient to case
inconsistencies.

I also added a filter that removes your own email addresses so you do not
accidentally filter out your own mail when selecting multiple emails. It can
always happen that one of your addresses is somewhere in the middle of a top or
cc list and gets overseen.

Fixed - Version 2.5 - 02/04/2014 - Use Group Template

Great work Axel!