flask/bin/pip install flask-mail

flask\Scripts\pip install --no-deps lamson chardet flask-mail

# email server
MAIL_SERVER = 'your.mailserver.com'
MAIL_PORT = 25
MAIL_USE_TLS = False
MAIL_USE_SSL = False
MAIL_USERNAME = 'you'
MAIL_PASSWORD = 'your-password'
 
# administrator list
ADMINS = ['you@example.com']

# email server
MAIL_SERVER = 'smtp.googlemail.com'
MAIL_PORT = 465
MAIL_USE_TLS = False
MAIL_USE_SSL = True
MAIL_USERNAME = 'your-gmail-username'
MAIL_PASSWORD = 'your-gmail-password'
 
# administrator list
ADMINS = ['your-gmail-username@gmail.com']

from flask.ext.mail import Mail
mail = Mail(app)

>>> from flask.ext.mail import Message
>>> from app import mail
>>> from config import ADMINS
>>> msg = Message('test subject', sender = ADMINS[0], recipients = ADMINS)
>>> msg.body = 'text body'
>>> msg.html = '<b>HTML</b> body'
>>> mail.send(msg)

from flask.ext.mail import Message
from app import mail
 
def send_email(subject, sender, recipients, text_body, html_body):
 msg = Message(subject, sender, recipients)
 msg.body = text_body
 msg.html = html_body
 mail.send(msg)

from flask import render_template
from config import ADMINS
 
def follower_notification(followed, follower):
 send_email("[microblog] %s is now following you!" % follower.nickname,
  ADMINS[0],
  [followed.email],
  render_template("follower_email.txt",
   user = followed, follower = follower),
  render_template("follower_email.html",
   user = followed, follower = follower))

Dear {{user.nickname}},
 
{{follower.nickname}} is now a follower. Click on the following link to visit {{follower.nickname}}'s profile page:
 
{{url_for("user", nickname = follower.nickname, _external = True)}}
 
Regards,
 
The microblog admin

<p>Dear {{user.nickname}},</p>
<p><a href="{{url_for("user", nickname = follower.nickname, _external = True)}}">{{follower.nickname}}</a> is now a follower.</p>
<table>
 <tr valign="top">
  <td><img src="{{follower.avatar(50)}}"></td>
  <td>
   <a href="{{url_for('user', nickname = follower.nickname, _external = True)}}">{{follower.nickname}}</a><br />
   {{follower.about_me}}
  </td>
 </tr>
</table>
<p>Regards,</p>
<p>The <code>microblog</code> admin</p>

from emails import follower_notification
 
@app.route('/follow/<nickname>')
@login_required
def follow(nickname):
 user = User.query.filter_by(nickname = nickname).first()
 # ...
 follower_notification(user, g.user)
 return redirect(url_for('user', nickname = nickname))

from threading import Thread
 
def send_async_email(msg):
 mail.send(msg)
 
def send_email(subject, sender, recipients, text_body, html_body):
 msg = Message(subject, sender = sender, recipients = recipients)
 msg.body = text_body
 msg.html = html_body
 thr = threading.Thread(target = send_async_email, args = [msg])
 thr.start()

from decorators import async
 
@async
def send_async_email(msg):
 mail.send(msg)
 
def send_email(subject, sender, recipients, text_body, html_body):
 msg = Message(subject, sender = sender, recipients = recipients)
 msg.body = text_body
 msg.html = html_body
 send_async_email(msg)

from threading import Thread
 
def async(f):
 def wrapper(*args, **kwargs):
  thr = Thread(target = f, args = args, kwargs = kwargs)
  thr.start()
 return wrapper