The email-account endpoints coerced user-supplied ports with a bare int(data.get("imap_port") or 993), so a non-numeric port (e.g. "imap") raised ValueError and surfaced as an HTTP 500 in the create, update, and test-config endpoints.
Add a _coerce_port(value, default) -> (port, error) helper and use it in all three endpoints, returning the endpoints standard {"ok": False, "error": ...} response (matching the existing "name required" validation) instead of crashing. A blank or missing port still falls back to the default (993/465).
Victor