[Geary] Geary using up bandwidth and I don't know why

[badrihippo disroot org]

Hi,
My Geary suddenly started using up bandwidth, and I'm not sure why.

I hadn't opened for ten days, while travelling, so I thought it could be downloading all the new emails i hadn't seen yet (my settings say to download for the past 2 weeks). But it kept on going, using over 500MB (my daily limit is 1.4GB) before I decided to shut it off. Now, whenever I start it, it seems to be going into download mode. One suspect is an email I received from a friend, which has 40MB worth of hi-res photos and hasn't loaded yet. But I'm pretty sure Geary should have finished it by now, without crossing hundreds of MBs!

Has anyone else run into this problem before? Any idea what could be going wrong?

Thanks in advance,
Badri