- Add DNS_CACHE_FALLBACK_ENABLED setting (default: true)
- Add in-process DNS cache (_dns_cache, _dns_cache_lock, _get/_set_cached_ipv4)
- Add _resolve_ipv4 (async) and _resolve_ipv4_sync: AF_INET lookup, cache on
success, return cached IP on EAI_AGAIN when fallback enabled
- Add _IMAP4SSLwithSNI: connects to pre-resolved IPv4 but uses original
hostname for TLS SNI/cert verification
- Add _POP3SSLWithIPv4Pref / _POP3WithIPv4Pref: override _create_socket to
use pre-resolved IPv4 while keeping original host for POP3_SSL SNI
- Add _make_pop3_conn factory and _make_imap_client async factory
- Wire IPv4/cache helpers into all 6 connection call-sites (IMAP x3, POP3 x3)
- Distinguish transient DNS (EAI_AGAIN) from permanent in _format_connection_error
- Replace asyncio.get_event_loop() with get_running_loop() in 4 async sites
- All 75 existing unit tests pass unchanged
Agent-Logs-Url: https://github.com/christianlouis/InboxConverge/sessions/be0a3bbd-1af1-408e-b918-84753723154b
Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>
copilot-swe-agent[bot]
45a2dd8be2