Proposal: Add an async email validation function using dnspython’s async resolver

I maintain a high-volume lead-gen API that validates thousands of emails per request. To keep latency low, we can’t rely on the library’s check_deliverability=True option because it triggers blocking DNS lookups. Instead, we run the library with deliverability checks disabled and perform our own async DNS queries via dns.asyncresolver.

It would be a real improvement if the library exposed a first-class async deliverability path. Below is a minimal prototype showing what that could look like:

from email_validator import validate_email, EmailNotValidError, ValidatedEmail
import dns.asyncresolver

dns_resolver = dns.asyncresolver.Resolver()

async def _resolve_mail_hosts(domain: str):
    try: return await dns_resolver.resolve(domain, "MX")
    except Exception:
        for record_type in ("A", "AAAA"):
            try: return await dns_resolver.resolve(domain, record_type)
            except Exception: continue
        return None

async def aio_validate_email(email: str) -> ValidatedEmail:
    email_info = validate_email(email, check_deliverability=False)
    if await _resolve_mail_hosts(email_info.domain) is None: raise EmailNotValidError
    return email_info

My plan is to open a PR that adds an async validator fully compatible with your existing Pydantic models, plus tests and documentation. Before I invest the time, are you open to adding async support to the project?

Bắt đầu bằng cách xem xét validate_email, ValidatedEmail, EmailNotValidError, các model Pydantic hiện có và luồng dns.asyncresolver được đề xuất. Công việc hoàn tất khi dự án có một trình xác thực khả năng gửi email bất đồng bộ hạng nhất tương thích với các model đó, cùng với các bài kiểm thử và tài liệu đã được lên kế hoạch.