Mailplane has a new look on Yosemite which is lighter and conforms better to the new OS X style. We hope you like it!
We noticed an uptick in crashes at the beginning of this year. After some sleepless nights and thanks to the help of our awesome customers we were finally able to track it down. Streak seems to trigger a bug in WebKit which causes Mailplane and Safari to crash.
We're in contact with the folks behind Streak to find a workaround but at the moment we can only suggest to temporarily disable Streak if you experience a lot of crashes. We'll let you know as soon as we have something ready.