diff --git a/CHANGELOG.md b/CHANGELOG.md
index 437f032..8c797ae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ Contributors add user-facing entries under `[Unreleased]` in the same PR. Mainta
 ### Changed
 
 - **Skill (`finance/wallet_screening` v2.0.0):** Report schema v2 with `verdict` (`ALLOW` / `REVIEW` / `DENY`), deterministic `risk_level`, `risk_factors[]`, and hop-1 `indirect_exposures` / `risky_counterparties`. Dual-emits `summary.risk_flag` and `summary.total_transactions` for v1 hosts ([#439](https://github.com/ARPAHLS/skillware/issues/439) slice 2).
+- **Typing:** `skillware/core/config.py` and `skillware/core/mail_config.py` are now type-clean and removed from the `[[tool.mypy.overrides]]` list, so `mypy skillware` checks them in CI (#415, Phase 2).
 
 ## [0.5.9] - 2026-10-20
 
diff --git a/pyproject.toml b/pyproject.toml
index bb5c81a..0c0ec1f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -274,8 +274,6 @@ warn_unused_configs = true
 module = [
     "skillware.cli",
     "skillware.core.loader",
-    "skillware.core.config",
-    "skillware.core.mail_config",
 ]
 ignore_errors = true
 
diff --git a/skillware/core/config.py b/skillware/core/config.py
index 8637a9c..3c0a2f9 100644
--- a/skillware/core/config.py
+++ b/skillware/core/config.py
@@ -249,7 +249,7 @@ def _merge_layers(layers: Sequence[ConfigLayer]) -> SkillwareConfig:
 
     mail = merge_mail_settings(mail_layers)
     evm = merge_evm_settings(evm_layers)
-    chains, chains_legacy = merge_chain_layers(layer.data for layer in layers)
+    chains, chains_legacy = merge_chain_layers([layer.data for layer in layers])
     if chains_legacy:
         extra = {**extra, "chains": chains_legacy}
 
diff --git a/skillware/core/mail_config.py b/skillware/core/mail_config.py
index 9300f64..75297f4 100644
--- a/skillware/core/mail_config.py
+++ b/skillware/core/mail_config.py
@@ -857,7 +857,7 @@ def validate_addressbook_data(data: Mapping[str, Any]) -> List[str]:
             )
             continue
 
-        if has_email:
+        if has_email and isinstance(emails, list):
             valid_email = False
             for entry in emails:
                 if not isinstance(entry, str) or not _EMAIL_RE.match(entry.strip()):
@@ -1087,7 +1087,7 @@ def clear_mail_signature_settings() -> List[Path]:
     for target in (project_config_write_path(), global_config_path()):
         if not target.is_file():
             continue
-        document = _read_yaml(target)
+        document = dict(_read_yaml(target))
         mail_block = document.get("mail")
         if not isinstance(mail_block, dict):
             continue