The lack of full-text search made me stop using Proton. I initially switched from Gmail and was happy with it until I couldn't find information a few times. I thought my emails have disappeared or that I couldn't remember (but I was sure it was there!) and thought I was going crazy. I found out the hard way that Proton actually is unable to search email contents and that's a dealbraker for me. At this point it's the most critical feature for me.
DarkStar
The lack of full-text search made me stop using Proton. I initially switched from Gmail and was happy with it until I couldn't find information a few times. I thought my emails have disappeared or that I couldn't remember (but I was sure it was there!) and thought I was going crazy. I found out the hard way that Proton actually is unable to search email contents and that's a dealbraker for me. At this point it's the most critical feature for me.