Fixes
- IMAP: automatic IPv4 fallback for broken IPv6 (#382). On networks where the IPv6 path completes the TCP connection but stalls the TLS handshake (broken path-MTU / filtered ICMPv6), account connections could hang for 30s and fail to sync. MailFlow now detects the stall and retries over IPv4 automatically, so a broken IPv6 route no longer blocks mail sync.
Upgrade: GHCR/image users pull 3.1.1; source builds pull main.