Changing expired password Error Code: 296

Bug Reports
1

Description

IMAP password for externl programs expired. Generated new one and put into mailspring:

mailsmtp Last Error Code: 296
mailsmtp Last Error Explanation: Unknown
mailsmtp Last Error Location: 10
mailsmtp Last Auth Type: 2

To Reproduce…

Steps to reproduce the behavior:

  1. add account with IMAP password for external program (i use ukr.net)
  2. password expired and generated a new one
  3. set the new password into mailspring
  4. mailsmtp Last Error Code: 296

    mailsmtp Last Error Explanation: Unknown
    mailsmtp Last Error Location: 10
    mailsmtp Last Auth Type: 2

Expected Behavior

should work normal with the new password

Screenshots

Setup

  • OS and Version: Windows 11 Pro 25H2
    • Installation Method: official image
  • Mailspring Version: 1.17.2

Additional Context

same password works well adding account to a browser mail
2

looks like same/similar to: Problem with SMTP login on version 1.17.2 Windows

3

have found this in config.json:

“syncState”: “invalid”,
“syncError”: {
“code”: 3221226505,
“error”: {
“stack”: “Error: null24872 [2026-01-28 09:35:39.874] [background] [critical] \r\n***\r\n*** Mailspring Sync \r\n*** An exception occurred during program execution: \r\n*** {“debuginfo”:“syncFoldersAndLabels - fetchAllFolders”,“key”:“ErrorAuthentication”,“offline”:false,“retryable”:false,“what”:“Unknown exception”}\r\n***\r\n\r\r\n\n at ChildProcess.onStreamCloseOrExit (file:///C:/Users/RUNNER~1/AppData/Local/Temp/nylas-build/electron-packager/tmp-n92MG5/resources/app/src/mailsync-process.ts:346:17)\n at ChildProcess.emit (node:events:519:28)\n at ChildProcess.emit (node:domain:489:12)\n at Process.ChildProcess._handle.onexit (node:internal/child_process:293:12)”,
“message”: “null24872 [2026-01-28 09:35:39.874] [background] [critical] \r\n***\r\n*** Mailspring Sync \r\n*** An exception occurred during program execution: \r\n*** {“debuginfo”:“syncFoldersAndLabels - fetchAllFolders”,“key”:“ErrorAuthentication”,“offline”:false,“retryable”:false,“what”:“Unknown exception”}\r\n***\r\n\r\r\n”
},
“signal”: null
},

and this ni logs:

29604 [2026-01-27 20:07:31.337] [foreground] [info] -X An SMTP error occurred: ErrorAuthentication LibEtPan code: 296
29604 [2026-01-27 20:07:31.367] [foreground] [error] [local-a27d9f31-2111] – Failed ({“debuginfo”:“ErrorAuthentication”,“key”:“send-failed”,“offline”:false,“retryable”:false,“what”:“Unknown exception”}). Changing status to complete

4

removing and adding account did not help (actually can not add the account because of the error)

5

switching to another ISP did not help

6

also, i think, you still need to allow adding an account if SMTP error or even SMTP is empty, i think it is helpful to have read-only accounts if required and which should not send any mails

7

works after updating to 1.17.3 version

but of course it is not guaranteed to be fixed and needs to be checked/tested.