535 5.7.3 Authentication unsuccessful_Office365 Smtp

[jan (Jan Doberstein)]

I suggest you use the power of the search in this community and find this:

How to configure email notifications Office365

This configuration setting expects the SMTP server to offer SMTP over SSL (SMTPS) but Office365 offers SSMTP (SMTP on submission port 587/tcp with optional connection upgrade with STARTTLS). See also: Yes. They are the credentials for the SMTP service. Without those, the SMTP service won’t allow you to send emails. No, HTTPS and SMTP/SSMTP/SMTPS have nothing to do with each other.