Apparently someone thought it would be a good idea to introduce extension signing into Mozilla Thunderbird. At the end of May 2015 Magnus Melin filed Bug 1168571: consider force signing add-ons requirements on in beta/release for thunderbird (too). So Mozilla is going to shoot themselves in the other foot if they are stupid enough to do this. A couple interesting points against this:
- Unlike Firefox, Thunderbird does not have issues with rogue add-ons
- Thunderbird dropped the ESR Branch a while back which would likely have to be reintroduced in order to support proprietary enterprise add-ons that shouldn’t be hosted on AMO.
It seems highly doubtful this is going to happen. However, in the off chance this did occur it wouldn’t likely be until Thunderbird 45 in March 2016.