Hi,
If you are getting 535 Incorrect Authentication Data error, it means your login credentials are invalid.
Please re-check, your username, password, port, authentication type, Encryption Mode with your Office 365 Team.
Please make sure you are using Authentication Type as Login.
Also, Make sure that your From Email Address and Username should be same.
Hope that makes senses!
Thanks
Support Team
Tech Banker
I checked all of those settings very carefully, the system is returning 535 even when using valid credentials (I’m the office 365 admin, my email/pass works)
How did resolve this?
I have same problem with office 365 account.
I didn’t – at least I didn’t get much help here.
It transpires that the issue is the type of office subscription – you need a P or an E level plan to send mail through a website.
I’ve got around it by using an alternative domain to send email from the website.