hi aaron,
to narrow down the issue, i’d like to collect some information:
1. which method of the smtp reply do you use, smtp relay or iis client submission?
2. when you mentioned “there are authentication errors from the setup”, can you upload a screenshot of the error message?
(1) click use rich formatting on the bottom of this thread->click insert image as the picture shows.
(2) on the pop-up window, click browse to select the screenshot. after it is uploaded, click insert.
3. based on the current situation, can you set up your office 365 accounts in outlook clients via smtp connection and send emails? here are the steps:
1) open outlook client -> file -> add account -> manual setup or additional server types -> pop or imap
2) on the following page, enter the following information: (account type is imap.)
3) please note: the *** Email address is removed for privacy *** is my office 365 email address.
4) in the email address field, please enter your office 365 email address.
5) in logion information region, enter your office 365 email address and password.
6) click more settings.
7) clicking ok according to the instructions.
best regards,
erick