About 15 seconds after every launch, the calContacts worker of mailsync starts CardDAV discovery for each account. Discovery calls https://id.getmailspring.com/api/resolve-dav-hosts, which returns 401 “Missing authentication” because there is no Mailspring ID. The resulting exception is not handled: mailsync logs a critical error with a stack trace and the process aborts. On KDE this triggers a DrKonqi crash notification (“mailsync has crashed”) for every account on every start.
Mail sync itself keeps working afterwards; only contact sync stops (“Stopping sync - unable to authenticate”).
This happens consistently: 12 times per account in the last 5 days, once per account on each app start.
Description
~/.var/app/com.getmailspring.Mailspring/config/Mailspring/mailsync-*.log
[2026-10-05 08:21:55.855] [main] [info] ------------- Starting Sync () ---------------
[2026-10-05 08:21:55.859] [metadata] [info] Metadata sync disabled, not logged in.
…
[2026-10-05 08:22:11.859] [calContacts] [info] Performing full CardDAV address book discovery
[2026-10-05 08:22:12.117] [calContacts] [critical]
*** Mailspring Sync
*** An exception occurred during program execution:
*** {“debuginfo”:“https://id.getmailspring.com/api/resolve-dav-hosts RETURNED {"statusCode":401,"error":"Unauthorized","message":"Missing authentication"}”,“key”:“Invalid Response Code: 401”,“offline”:false,“retryable”:false, …}
[2026-10-05 08:22:12.117] [calContacts] [critical] *** Stack trace (line numbers are approximate):
*** ??:? stringbuf::~stringbuf()
*** ??:? string::_M_replace_aux(unsigned long, unsigned long, unsigned long, char)
*** …
*** ??:? __clone()
[2026-10-05 08:22:12.117] [calContacts] [info] Stopping sync - unable to authenticate.
To Reproduce…
Steps to reproduce the behavior:
-
Fresh install, choose to continue without a Mailspring ID during onboarding
-
Add a generic IMAP account.
-
Restart Mailspring and wait ~15 s → mailsync aborts in
calContacts, crash reporter of the desktop shows a crash.
Expected Behavior
Using Mailspring without an ID is an officially supported mode. In that mode, CardDAV discovery via resolve-dav-hosts should be skipped (or the 401 handled gracefully, e.g. log a warning and fall back to well-known/SRV discovery or disable contact sync) instead of aborting the sync process.
Screenshots
Setup
Environment
- Mailspring 1.25.0 (Flatpak from Flathub, runtime org.freedesktop.Platform 26.08)
- Fedora Linux 44, KDE Plasma 6.7.5 (Wayland)
- 2 generic IMAP/SMTP accounts (self-hosted provider, no Gmail/Office365)
- Not signed in with a Mailspring ID (opted out during setup, as offered by the onboarding)
- OS and Version:
- Installation Method:
- Mailspring Version: