Outlook Office 365 "Send Mail As" Email Authentication Error

Copper Contributor

My work has recently created an office 365 email account for me and I need to use this new email address as an alias for my current google email address when communicating with clients. 


I have done the following steps:

In my Gmail setting I have enabled POP and IMAP


Then under accounts and imports I selected add another email address. Here I typed in my outlook email and hit "next"


I am then asked for SMTP server, email and password. Email and password is my outlook email and password, and for SMTP server I have tried the following which I found under my "Oulook" -> "mail" -> "sync email" settings:


Server name: smtp.office365.com
Port: 587
Encryption method: STARTTLS


This has not worked and I continue to get authentication errors. I have noticed my POP options are greyed out in my outlook app. 


Any ideas?



1 Reply
This can be blocked on several levels from O365 side, so best talk with your IT folks first. For example, basic authentication might be disabled, the POP/IMAP/SMTP protocols might be disabled, there might be a Conditional access policy requiring MFA, and so on.