I had to move all my projects to a different provider after Acumbamail triggered 'Social Engineering' warnings from Google multiple times. The first time it happened, support claimed to fix it. When it happened again, I realized their infrastructure is simply not safe for professional use. Having your domain flagged as a 'scam' by Google twice is a death sentence for SEO and client trust. If you don't want to spend your weekends migrating providers and pleading with Google to unblock your site, avoid this service.

EDIT:

I disagree that the team works on fixing issues. I waited a few days for my first note from Google to the team to fix the problem. However, when I contacted them, they resolved it within a few days. For the second time, they neglected the issue for over a week, so instead of asking them again, I moved the project to another platform. Surprisingly, an old project was stuck for a longer time, and it took me a few weeks for the team to fix it in auto mode without my direct request. Therefore, I don’t believe their team works on cases like that immediately. You have notifications, you have to send requests, you have to wait for the fix, you have to open a case in Google, and then it might or might not be fixed. The problem is that it took at least a week for an issue like that to be resolved. I’ve never encountered such a problem with other services. I believe their infrastructure architecture is not properly configured.