Can't use emails on my account

Since may 14, despite having a Pro license, I do not receive emails on my Windows 10 using Firefox OS, however I did received them on my Ipad. Upgraded to version 9 and paid again 29,95 Euro. No solution.
The problems getting bigger while trying to figure out what went wrong. I lost my inbox emails at some moment.
The problem seems to occur only on my main account, could it be that my account settings needed to change ? Since may 14, the power of my computer was off because of a 11-week away from home.
Any help is much appreciated.
Thank you,