Greetings,
We have multiple domains and have email aliases for each. Yesterday someone discovered they were not able to send from one of the aliases yet they had been able to do so for years. We tested and they are correct. When typing in the alias email address into the From field (after clicking From in Outlook new email), it is grayed out and the primary SMTP is still there.
FYI, we moved to office 365 from on prem last summer (I was not here for that) but do still have the on prem server. From what I can tell it doesn't do anything in regard to sending out or receiving emails. We use barracudas for spam filtering and other email security and just last week migrated from our on prem appliances to the barracuda cloud appliance. However, we do not send out through the barracuda so doubt this is related but wanted to mention.
I am unable to edit aliases in Office 365. I get a message stating it is being synced from local AD. I then went to edit it through the EAC and received the same message. I do not see where aliases are in AD.
Any help troubleshooting this is greatly appreciated.
https://techcommunity.microsoft.com/t5/Office-365/Sending-email-as-alias-in-office365/td-p/60802
interesting that it is stated multiple times in the above link that sending and receiving from an alias cannot be done through typical Outlook usage, but some users are telling me that they previously could do this (including a senior manager in IT who has been here 12 years or so).