The start page appeal to donate can’t currently be turned off. If you like, you can change the start page to something else. To do this, in Thunderbird go to Options | General
Pósćiwańske napšašowanje na startowem boku njedajo se tuchylu znjemóžniś. Jolic cośó, móžośo drugi startowy bok wužywaś. Aby to cynił, źiśo do Nastajenja | Powšykne w Thunderbird