my problems with Thunderbird are more complex. # 1 The user interface is ambiguous. Sometimes you quit an e-mail via the status banner sometimes via the cross in the upper right corner. * I never can find how to alter delete or add adresbooks on my Synology server * Altering appointments is impossible * moving to a dat is impossible 9only via work around a detected * complete lack of documentation where I can find answers * This way Thunderbird cost me hours, so not say days. Despite I hate Microsoft and believe in applications like Thunderbird I'm seriously thinking of return into outlook or office 365. Thunderbird is not a religion but just a tool