Seems to work correctly for me now on Thunderbird 52.9.1 (64-bit) and Ubuntu 18.04.1 (Gnome 3.28.2) all updates applied to date. Samba server is running smb protocol v3.
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to thunderbird in Ubuntu. https://bugs.launchpad.net/bugs/1515288 Title: Thunderbird attachment from Samba share won't send Status in thunderbird package in Ubuntu: Confirmed Bug description: Ubuntu 14.04.3 - Thunderbird 38.3.0 Samba shares are mounted and accessible via Files file manager. Drag-n-Drop file from mounted Samba share into new Email attachments area works. Cannot send email due to: "Sending of the message failed. There was an error attaching smb://server/path/to/file. Please check that you have access to the file." This bug report about what seems to be the same issue was opened in 2007 > https://bugs.launchpad.net/ubuntu/+source/mozilla-thunderbird/+bug/105088 In April 2014 it was marked as "Fix released" - not sure what that means ... because it's not working here. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/1515288/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp

