Here is the code snippet of config:
app.config['MAIL_SERVER'] = 'smtp.gmail.com'
app.config['MAIL_PORT'] = '465'
app.config['MAIL_USE_TLS'] = False
app.config['MAIL_USE_SSL'] = True
app.config['MAIL_USERNAME'] = 'my email here'
app.config['MAIL_PASSWORD'] = 'password here'
When I test without Apache, all the code worked well. But When I test with Apache, SMTPSenderRefused occured. This is the entire error info: SMTPSenderRefused: (530, '5.5.1 Authentication Required. Lea more atn5.5.1 https://support.google.com/mail/answer/14257 s23sm10937096pfj.86 - gsmtp',
It seemed the password wasn't passed to gmail.
Is it the problem of apache? Thank you!