Exchange Online mail spammed

[BFOFANA]

Hello,

I have an Exchange Server 2016 environment that I am migrating to Exchange Online. The hybrid configuration has already been done.
Meanwhile, users migrated to Exchange are seeing their emails spammed when they send to other Exchange Online users belonging to other Office 365 holders. Before the migration, they did not have this problem.
If someone can help me to find the cause of the problem

Regards

[#2]

Hey @BFOFANA, can you please explain in detail what do you mean by emails are spammed ? Are their emails are landing in recipients' Spam folder ?

Also what is your Outbound mailflow like ?

Have you added SPF record for Exchange online in your Public DNS ?

You can ask the recipient for the original email and then check the email header in message analyser, i prefer this one https://mha.azurewebsites.net/