Why is no updates for Thunderbird in Snap Store for Ubuntu?
I install Thunderbird 60.6.1 (64-bit) from Ubuntu Software (Ubuntu 18.04) couple of month ago. Constantly see window with message about new update available and Thunderbird cant install this update. It looks strange for application installed from OS native Store. Then I have 2 questions: 1) Is it possible to setup Ubuntu or Thunderbird to automatically update it by himself passing Ubuntu Store? 2) In another case, why Thunderbird has no updates in Ubuntu Store (Snap Store)?
Alla svar (1)
Two issues here.
1. Ubuntu is nothing to do with the Thunderbird project. So issues around their repository would need to be addressed to the repository maintiners, whom ever they are.
2. The version of Thunderbird you obtain from that source may not be the same as the one the Thunderbird team releases. Maintainers frequently release a "personalised" version just for their release of Linux that has things changed to suit the maintainers.
I suggest you install Thunderbird from the thunderbird.net web site. Then we have a known basis to answer questions of this sort.
https://support.mozilla.org/en-US/kb/installing-thunderbird-linux