I have just gone and made changes to the attachments for our group.
It has been a long time since I have needed to make a change, but I notice there is two option.
Store On Site - Remove from emails.
Send In Emails - Not Store On Site.
I have taken the later option because, as mentioned, not everyone has a Yahoo account to access the archives.
If after a trial period it is felt that the 'Store On Site' option is preferred, this can always be changed.
Please not, as far as I am aware these attachments will only be received by those on 'Individual Email' and not by those on 'Daily Digest' or 'No Email' settings. This appears to be the case on my other groups.
Lets see how we go.
Anyone wish to trial an attachment now? :-)