o365 email plugin and formbuilder

Hey there, wondering if you can help.

So i installed the following plugin on our wordpress “Mail Integration for Office 365/Outlook”. This allows me to make an API type connection to o365 and use a mail account to send mail. This overcomes the problem of messages being marked as junk when the webhost is sending mail from wordpress.

The plugin works, i can send test mail. I can send mail from a “mail log” plugin that i installed to try and get to the bottom of the problem. However no form will send the mail, at all, if i turn on that plugin. With the normal webhost mail it works.

tried:
– changing the email in settings to be the same email as i got the o365 plugin to use
– made sure all emails are in the same domain
– changed the reply to email to the exact email address (was at the same domain previously)
– tested to make sure plugin works and sends mail correctly (it does).

None of this has helped and no matter what form builder refuses to send through 0365, while other plugins send fine. Any ideas?