I'm using Python's smtplib module and these SMTP settings:
SMTP_PORT = 587
SMTP_SERVER_ADDRESS = {
'gmail' : 'smtp.gmail.com',
'outlook': 'smtp-mail.outlook.com',
'yahoo' : 'smtp.mail.yahoo.com'
}
In my tests and everyday usage, I only use Yahoo.
I have never tested Gmail but the code is there to support it.
I tested Outlook but found that messages were delayed by a lot. One time, I received messages 12 hours later! Maybe something I did wrong, not sure, and never tried to debug it.