[Geary] Responsivity issue on startup

[Amadeus Folego <amadeusfolego gmail com>]

Hello,

I've been using Geary for a while, and it has been great!

However, sometimes I want to check an old message or simply browse my emails but when Geary is loading messages it gets unresponsive, I can just see the loading spinner (v0.11.3). 

I'd like to investigate this issue and contribute to Geary to make it even better.

Since Github issues are disabled and I did not receive a response on the IRC channel, I thought I could send this email.

If there's already someone on this issue or it's a wontfix it's fine as well.

Thanks, Amadeus.