My log looks a bit different.
Mailspring Version: 1.9.0-87660767
Platform: win32
Account State: sync_error
Account Provider: imap
IMAP Server: mail.customserver.com
SMTP Server: mail.customserver.com
--------------------------------------------
2836 [2021-04-15 16:14:08.216] [background] [info] syncFolderChangesViaCondstore - INBOX.Mailspring.Snoozed: modseq 1 to 1, uidnext 1 to 1
2836 [2021-04-15 16:14:08.219] [background] [info] syncFolderChangesViaCondstore - INBOX.Sometime: modseq 5 to 5, uidnext 5 to 5
2836 [2021-04-15 16:14:08.222] [background] [info] syncFolderChangesViaCondstore - INBOX.Follow Up: modseq 5 to 5, uidnext 3 to 3
2836 [2021-04-15 16:14:08.225] [background] [info] syncFolderChangesViaCondstore - INBOX.Marketing: modseq 3 to 3, uidnext 3 to 3
2836 [2021-04-15 16:14:08.228] [background] [info] syncFolderChangesViaCondstore - INBOX.Clients: modseq 1 to 1, uidnext 1 to 1
2836 [2021-04-15 16:14:08.231] [background] [info] syncFolderChangesViaCondstore - INBOX.Clients.PRIVATE: modseq 25 to 25, uidnext 17 to 17
2836 [2021-04-15 16:14:08.234] [background] [info] syncFolderChangesViaCondstore - INBOX.Clients.PRIVATE: modseq 68 to 68, uidnext 41 to 41
2836 [2021-04-15 16:14:08.234] [background] [info] Sync loop deleting unlinked messages with phase 1.
2836 [2021-04-15 16:14:08.234] [background] [info] Sync loop complete.
2836 [2021-04-15 16:14:47.259] [foreground] [info] Idle exited with code 1
2836 [2021-04-15 16:14:47.313] [foreground] [info] syncFolderChangesViaCondstore - INBOX: modseq 3449 to 3449, uidnext 1434 to 1434
2836 [2021-04-15 16:14:47.313] [foreground] [info] Idling on folder INBOX
2836 [2021-04-15 16:15:32.551] [foreground] [info] Idle exited with code 0
2836 [2021-04-15 16:15:32.554] [foreground] [info] syncFolderChangesViaCondstore - INBOX: modseq 3449 to 3450, uidnext 1434 to 1435
2836 [2021-04-15 16:15:32.574] [foreground] [info] syncFolderChangesViaCondstore - Changes since HMODSEQ 3449: 1 changed, 0 vanished
2836 [2021-04-15 16:15:32.639] [foreground] [info] Idling on folder INBOX
2836 [2021-04-15 16:15:39.067] [main] [info] [local-976ef08c-ba5c] Running ChangeUnreadTask performLocal:
2836 [2021-04-15 16:15:39.077] [main] [info] [local-976ef08c-ba5c] -- Succeeded. Changing status to `remote`
2836 [2021-04-15 16:15:39.390] [foreground] [info] Idle exited with code 0
2836 [2021-04-15 16:15:39.390] [foreground] [info] [local-976ef08c-ba5c] Running ChangeUnreadTask performRemote:
2836 [2021-04-15 16:15:39.398] [foreground] [info] [local-976ef08c-ba5c] -- Succeeded. Changing status to `complete`
2836 [2021-04-15 16:15:39.402] [foreground] [info] syncFolderChangesViaCondstore - INBOX: modseq 3450 to 3451, uidnext 1435 to 1435
2836 [2021-04-15 16:15:39.405] [foreground] [info] syncFolderChangesViaCondstore - Changes since HMODSEQ 3450: 1 changed, 0 vanished
2836 [2021-04-15 16:15:39.406] [foreground] [info] Idling on folder INBOX
2836 [2021-04-15 16:16:00.476] [metadata] [info] Metadata delta stream closed.
2836 [2021-04-15 16:16:00.477] [metadata] [info] Metadata delta stream starting...
This happens with all 4 of my accounts.
My other accounts give authentication errors
Mailspring Version: 1.9.0-87660767
Platform: win32
Account State: invalid
Account Provider: imap
IMAP Server: mail.privateserver.com
SMTP Server: mail.privateserver.com
--------------------------------------------
***
13812 [2021-04-16 08:53:58.263] [main] [info] Identity created at 1593175754 - using ID Schema 1
13812 [2021-04-16 08:53:58.265] [main] [info] ------------- Starting Sync (hello@privatedomain.com) ---------------
13812 [2021-04-16 08:53:58.268] [background] [info] Marking all folders as `busy`
13812 [2021-04-16 08:53:58.269] [metadata] [info] Metadata delta stream starting...
13812 [2021-04-16 08:53:58.270] [background] [info] Syncing folder list...
13812 [2021-04-16 08:54:04.161] [background] [critical]
***
*** Mailspring Sync
*** An exception occurred during program execution:
*** {"debuginfo":"syncFoldersAndLabels - fetchAllFolders","key":"ErrorAuthentication","retryable":false,"what":"Unknown exception"}
***
14036 [2021-04-16 08:54:09.654] [main] [info] Identity created at 1593175754 - using ID Schema 1
14036 [2021-04-16 08:54:09.656] [main] [info] ------------- Starting Sync (hello@privatedomain.com) ---------------
14036 [2021-04-16 08:54:09.660] [background] [info] Marking all folders as `busy`
14036 [2021-04-16 08:54:09.661] [metadata] [info] Metadata delta stream starting...
14036 [2021-04-16 08:54:09.662] [background] [info] Syncing folder list...
14036 [2021-04-16 08:54:16.290] [background] [critical]
***
*** Mailspring Sync
*** An exception occurred during program execution:
*** {"debuginfo":"syncFoldersAndLabels - fetchAllFolders","key":"ErrorAuthentication","retryable":false,"what":"Unknown exception"}
***
5928 [2021-04-16 08:54:18.484] [main] [info] Identity created at 1593175754 - using ID Schema 1
5928 [2021-04-16 08:54:18.485] [main] [info] ------------- Starting Sync (hello@privatedomain.com) ---------------
5928 [2021-04-16 08:54:18.491] [background] [info] Marking all folders as `busy`
5928 [2021-04-16 08:54:18.491] [metadata] [info] Metadata delta stream starting...
5928 [2021-04-16 08:54:18.493] [background] [info] Syncing folder list...
5928 [2021-04-16 08:54:20.233] [background] [critical]
***
*** Mailspring Sync
*** An exception occurred during program execution:
*** {"debuginfo":"syncFoldersAndLabels - fetchAllFolders","key":"ErrorAuthentication","retryable":false,"what":"Unknown exception"}
***
11488 [2021-04-16 08:54:47.690] [main] [info] Identity created at 1593175754 - using ID Schema 1
11488 [2021-04-16 08:54:47.691] [main] [info] ------------- Starting Sync (hello@privatedomain.com) ---------------
11488 [2021-04-16 08:54:47.695] [background] [info] Marking all folders as `busy`
11488 [2021-04-16 08:54:47.695] [metadata] [info] Metadata delta stream starting...
11488 [2021-04-16 08:54:47.697] [background] [info] Syncing folder list...
11488 [2021-04-16 08:54:49.963] [background] [critical]
***
*** Mailspring Sync
*** An exception occurred during program execution:
*** {"debuginfo":"syncFoldersAndLabels - fetchAllFolders","key":"ErrorAuthentication","retryable":false,"what":"Unknown exception"}
***