I have a client that uses Office365 for their emails. They have an internet connection through a 3rd party. The users are able to send & receive emails in Office365 without any issues.
However, they have an application which requires details of a SMTP server & authentication to send emails to the other users. We have tried smtp.office365.com - 587 - TLS to no avail. I cannot use the smtp details of the ISP as we do not have an email account with them to authenticate.
All suggestions are much appreciated. I have tried creating a gmail account & sending emails thru smtp.gmail.com with no success.