Hallo,
ich bin dabei meine Mailadresse von mail.de in Mailspring einzutragen.
Habe in meiner Mailadresse imap und smtp aktiviert. Muss aber beim Eintrag in Mailspring die Angabe “Costum Container Folder” ausfüllen und weiß leider nicht, was ich dort eintragen muss.
The “Custom Container Folder” field is an IMAP namespace prefix — it tells Mailspring where your mailbox hierarchy begins on the server. For most providers (including mail.de) you can leave it blank and Mailspring will detect the correct structure automatically. If your mail.de account has a nested folder structure and sync seems incomplete after connecting, try entering INBOX there. Otherwise, leave it empty and let auto-detection handle it.