have 3 accounts connected (gmail & gsuite) but only 1 keeps having sync error. IMAP is also enabled in that account in gmail settings.
After connection it works perfectly fine. But every time PC restarts or turned on the following day I always got this red error thing.
GMail
This issue is becoming quite annoying.
Same for me, with a Gmail account.
I have CONNECTION PROBLEM with HOTMAIL
Been waiting for a solution to this.
Same for me, i was one off the first to say that, never got a answer 
same here, logs:
13552 [2021-07-01 08:12:24.001] [main] [info] Identity created at 1584404126 - using ID Schema 1
13552 [2021-07-01 08:12:24.003] [main] [info] ------------- Starting Sync (douugbr@gmail.com) ---------------
13552 [2021-07-01 08:12:24.007] [metadata] [info] Metadata delta stream starting...
13552 [2021-07-01 08:12:27.017] [background] [info] Fetching XOAuth2 access token (gmail) for 8cf390db
13552 [2021-07-01 08:12:27.414] [background] [critical]
***
*** Mailspring Sync
*** An exception occurred during program execution:
*** {"debuginfo":"https://www.googleapis.com/oauth2/v4/token RETURNED {\n \"error\": \"invalid_grant\",\n \"error_description\": \"Bad Request\"\n}","key":"Invalid Response Code: 400","retryable":false,"what":"Unknown exception"}
***
7448 [2021-07-01 08:12:28.433] [main] [info] Identity created at 1584404126 - using ID Schema 1
7448 [2021-07-01 08:12:28.435] [main] [info] ------------- Starting Sync (douugbr@gmail.com) ---------------
7448 [2021-07-01 08:12:28.441] [metadata] [info] Metadata delta stream starting...
7448 [2021-07-01 08:12:31.449] [background] [info] Fetching XOAuth2 access token (gmail) for 8cf390db
7448 [2021-07-01 08:12:31.818] [background] [critical]
***
*** Mailspring Sync
*** An exception occurred during program execution:
*** {"debuginfo":"https://www.googleapis.com/oauth2/v4/token RETURNED {\n \"error\": \"invalid_grant\",\n \"error_description\": \"Bad Request\"\n}","key":"Invalid Response Code: 400","retryable":false,"what":"Unknown exception"}
***
11148 [2021-07-01 08:12:32.716] [main] [info] Identity created at 1584404126 - using ID Schema 1
11148 [2021-07-01 08:12:32.718] [main] [info] ------------- Starting Sync (douugbr@gmail.com) ---------------
11148 [2021-07-01 08:12:32.722] [metadata] [info] Metadata delta stream starting...
11148 [2021-07-01 08:12:35.723] [background] [info] Fetching XOAuth2 access token (gmail) for 8cf390db
11148 [2021-07-01 08:12:36.099] [background] [critical]
***
*** Mailspring Sync
*** An exception occurred during program execution:
*** {"debuginfo":"https://www.googleapis.com/oauth2/v4/token RETURNED {\n \"error\": \"invalid_grant\",\n \"error_description\": \"Bad Request\"\n}","key":"Invalid Response Code: 400","retryable":false,"what":"Unknown exception"}
***Hey,
I can confirm that I experience the same issue, too.
Additionally, this issue does not seem to be verification-type related, as I have an account that uses IMAP and XOAuth2; and both are affected by this issue.
Finally, my desync happens very reliably:
Logs:
error_XOAuth2.txt (3.1 KB) error_IMAP.txt (3.0 KB)
Can confirm the same issues for outlook accounts. I had tried everything but the syncing still failed: reinstalling mailspring, remove the cached data and delete the entire appdata folder.
5 accounts, all Gmail, all using direct Gmail method (as opposed to IMAP). Most recently-added account needs re-authenticating/re-connecting every time I start Mailspring.
Same here but for me, all Gmail accounts are working ok, but one custom server account has the same problem people are talking about.
Mailspring Version: 1.9.1-30ef802f
Platform: win32
Account State: sync_error
Account Provider: imap
IMAP Server: imap.hostinger.es
SMTP Server: smtp.hostinger.es36964 [2021-08-18 00:15:38.098] [background] [info] syncFolderChangesViaCondstore - INBOX.Sent: modseq 29 to 29, uidnext 264 to 264
36964 [2021-08-18 00:15:38.146] [background] [info] syncFolderChangesViaCondstore - INBOX.Drafts: modseq 3 to 3, uidnext 2 to 2
36964 [2021-08-18 00:15:38.193] [background] [info] syncFolderChangesViaCondstore - INBOX.Trash: modseq 4 to 4, uidnext 3 to 3
36964 [2021-08-18 00:15:38.240] [background] [info] syncFolderChangesViaCondstore - INBOX.Junk: modseq 1 to 1, uidnext 106 to 106
36964 [2021-08-18 00:15:38.287] [background] [info] syncFolderChangesViaCondstore - INBOX.Trash.Archives: modseq 1 to 1, uidnext 1 to 1
36964 [2021-08-18 00:15:38.334] [background] [info] syncFolderChangesViaCondstore - INBOX.Trash.Archives.2019: modseq 2 to 2, uidnext 2 to 2
36964 [2021-08-18 00:15:38.381] [background] [info] syncFolderChangesViaCondstore - INBOX.Mailspring: modseq 1 to 1, uidnext 1 to 1
36964 [2021-08-18 00:15:38.429] [background] [info] syncFolderChangesViaCondstore - INBOX.Mailspring.Snoozed: modseq 1 to 1, uidnext 1 to 1
36964 [2021-08-18 00:15:38.429] [background] [info] Sync loop deleting unlinked messages with phase 1.
36964 [2021-08-18 00:15:38.429] [background] [info] Sync loop complete.
36964 [2021-08-18 00:16:38.997] [foreground] [info] Idle exited with code 0
36964 [2021-08-18 00:16:39.041] [foreground] [info] syncFolderChangesViaCondstore - INBOX: modseq 225 to 225, uidnext 1777 to 1777
36964 [2021-08-18 00:16:39.045] [foreground] [info] Idling on folder INBOX
36964 [2021-08-18 00:17:38.443] [background] [info] Syncing folder list…
36964 [2021-08-18 00:17:38.585] [background] [info] syncFolderChangesViaCondstore - INBOX: modseq 225 to 225, uidnext 1777 to 1777
36964 [2021-08-18 00:17:38.636] [background] [info] syncFolderChangesViaCondstore - INBOX.Sent: modseq 29 to 29, uidnext 264 to 264
36964 [2021-08-18 00:17:38.684] [background] [info] syncFolderChangesViaCondstore - INBOX.Drafts: modseq 3 to 3, uidnext 2 to 2
36964 [2021-08-18 00:17:38.738] [background] [info] syncFolderChangesViaCondstore - INBOX.Trash: modseq 4 to 4, uidnext 3 to 3
36964 [2021-08-18 00:17:38.785] [background] [info] syncFolderChangesViaCondstore - INBOX.Junk: modseq 1 to 1, uidnext 106 to 106
36964 [2021-08-18 00:17:38.832] [background] [info] syncFolderChangesViaCondstore - INBOX.Trash.Archives: modseq 1 to 1, uidnext 1 to 1
36964 [2021-08-18 00:17:38.879] [background] [info] syncFolderChangesViaCondstore - INBOX.Trash.Archives.2019: modseq 2 to 2, uidnext 2 to 2
36964 [2021-08-18 00:17:38.926] [background] [info] syncFolderChangesViaCondstore - INBOX.Mailspring: modseq 1 to 1, uidnext 1 to 1
36964 [2021-08-18 00:17:38.973] [background] [info] syncFolderChangesViaCondstore - INBOX.Mailspring.Snoozed: modseq 1 to 1, uidnext 1 to 1
36964 [2021-08-18 00:17:38.973] [background] [info] Sync loop deleting unlinked messages with phase 2.
36964 [2021-08-18 00:17:38.973] [background] [info] Sync loop complete.
This issue is allmost overkilling for me, still no fix for this?
Same issue here using gmail.
Same here. 4 accounts : 2 IMAP with no problem.
1 gmail > need to reconnect each time PC restart
1 hotmail > need to reconnect each time PC restart
I have this problem too… with 3 gmail/gsuite accounts. Everytime my computer restarts I have to reconnect all 3 accounts.
Same problem here, has anyone been able to find a fix?
Confirming the same issue, only occurring in Windows (not in my Linux installation), and affecting both google and fastmail (imap) accounts.
Happening once again for me too…
I FOUND A FIX
Solution:
It has been working for me now for over a week without any problems with all my accounts
Same issue for me as well. Hotmail and Gmail.
What i don’t understand is that this issue is already surfacing since version 1.9.1 and 1.9.2, the latest version.
Why does it take so long for a fix?
I tried the above mentioned solution from @adawg as well, although with version 1.9.0. since this was the latest version before the syncing issues surfaced(if i’m correct…), but after a restart it got updated to the latest version, so that did not help either.
Maybe a good idea is to implement an option to disable automatic updates? 
