The quote reply pref (reply below/above) is currently being moved to the account settings (bug 141531 comment #46, so it may be a good idea to move the (related) "Forward" setting there as well (for aesthetic reasons). Since I use "Inline" for all my accounts, I'm not sure if this bug is needed. However, if there is some need to be able to differentiate between "inline" and "attachment" on a per-account basis, then this bug should be fixed. I prolly should have asked this in the NGs first, but didn't want to lose track of it there. Sorry for bug-spam. :-\
sorry for the spam. making bugzilla reflect reality as I'm not working on these bugs. filter on FOOBARCHEESE to remove these in bulk.
Filter on "Nobody_NScomTLD_20080620"
I think that it would be best to also have the setting in each account's options, but leave it in the main options as well. The one in the main options should be renamed to 'Global forwarding policy' or 'Default forwarding behavior'. A list box with all accounts should be added there, with checkboxes/radio-buttons next to them. It would reflect the setting in each account options and allow the user to preview which accounts have that option set to inline and which ones as attachment. That would also allow them to change it and changes should be applied/mirrored in each account's own settings.
So, which account will be used to determine the option? That of the message being forwarded? What if the user chooses a different account in the message composition window? Will the forwarding mode change?