Feat: Add box connector (#11845)

### What problem does this PR solve?

Feat: Add box connector

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

api/utils/email_templates.py

@@ -20,18 +20,18 @@ Reusable HTML email templates and registry.
 
 # Invitation email template
 INVITE_EMAIL_TMPL = """
-<p>Hi {{email}},</p>
-<p>{{inviter}} has invited you to join their team (ID: {{tenant_id}}).</p>
-<p>Click the link below to complete your registration:<br>
-<a href="{{invite_url}}">{{invite_url}}</a></p>
-<p>If you did not request this, please ignore this email.</p>
+Hi {{email}},
+{{inviter}} has invited you to join their team (ID: {{tenant_id}}).
+Click the link below to complete your registration:
+{{invite_url}}
+If you did not request this, please ignore this email.
 """
 
 # Password reset code template
 RESET_CODE_EMAIL_TMPL = """
-<p>Hello,</p>
-<p>Your password reset code is: <b>{{ code }}</b></p>
-<p>This code will expire in {{ ttl_min }} minutes.</p>
+Hello,
+Your password reset code is: {{ code }}
+This code will expire in {{ ttl_min }} minutes.
 """
 
 # Template registry

api/utils/web_utils.py

@@ -20,9 +20,10 @@ import json
 import re
 import socket
 from urllib.parse import urlparse
-
-from api.apps import smtp_mail_server
-from flask_mail import Message
+import aiosmtplib
+from email.mime.text import MIMEText
+from email.header import Header
+from common import settings
 from quart import render_template_string
 from api.utils.email_templates import EMAIL_TEMPLATES
 from selenium import webdriver
@@ -36,10 +37,10 @@ from webdriver_manager.chrome import ChromeDriverManager
 
 
 OTP_LENGTH = 8
-OTP_TTL_SECONDS = 5 * 60
-ATTEMPT_LIMIT = 5
-ATTEMPT_LOCK_SECONDS = 30 * 60
-RESEND_COOLDOWN_SECONDS = 60
+OTP_TTL_SECONDS = 5 * 60 # valid for 5 minutes
+ATTEMPT_LIMIT = 5 # maximum attempts
+ATTEMPT_LOCK_SECONDS = 30 * 60 # lock for 30 minutes
+RESEND_COOLDOWN_SECONDS = 60 # cooldown for 1 minute
 
 
 CONTENT_TYPE_MAP = {
@@ -183,27 +184,34 @@ def get_float(req: dict, key: str, default: float | int = 10.0) -> float:
         return parsed if parsed > 0 else default
     except (TypeError, ValueError):
         return default
+    
+
+async def send_email_html(to_email: str, subject: str, template_key: str, **context):
+
+    body = await render_template_string(EMAIL_TEMPLATES.get(template_key), **context)
+    msg = MIMEText(body, "plain", "utf-8")
+    msg["Subject"] = Header(subject, "utf-8")
+    msg["From"] = f"{settings.MAIL_DEFAULT_SENDER[0]} <{settings.MAIL_DEFAULT_SENDER[1]}>"
+    msg["To"] = to_email
+
+    smtp = aiosmtplib.SMTP(
+        hostname=settings.MAIL_SERVER,
+        port=settings.MAIL_PORT,
+        use_tls=True,
+        timeout=10,
+    )
+
+    await smtp.connect()
+    await smtp.login(settings.MAIL_USERNAME, settings.MAIL_PASSWORD)
+    await smtp.send_message(msg)
+    await smtp.quit()
 
 
-def send_email_html(subject: str, to_email: str, template_key: str, **context):
-    """Generic HTML email sender using shared templates.
-    template_key must exist in EMAIL_TEMPLATES.
-    """
-    from api.apps import app
-    tmpl = EMAIL_TEMPLATES.get(template_key)
-    if not tmpl:
-        raise ValueError(f"Unknown email template: {template_key}")
-    with app.app_context():
-        msg = Message(subject=subject, recipients=[to_email])
-        msg.html = render_template_string(tmpl, **context)
-        smtp_mail_server.send(msg)
-
-
-def send_invite_email(to_email, invite_url, tenant_id, inviter):
+async def send_invite_email(to_email, invite_url, tenant_id, inviter):
     # Reuse the generic HTML sender with 'invite' template
-    send_email_html(
-        subject="RAGFlow Invitation",
+    await send_email_html(
         to_email=to_email,
+        subject="RAGFlow Invitation",
         template_key="invite",
         email=to_email,
         invite_url=invite_url,
@@ -230,4 +238,4 @@ def hash_code(code: str, salt: bytes) -> str:
 
 def captcha_key(email: str) -> str:
     return f"captcha:{email}"
-    
+