Hi ​@Jeremie Gagnon 

Thanks for seeking help from the community. I can understand why this would be alarming.

When you say that the Bounce Rate has suddenly increased, do you mean that the last Campaign send shows that, or does it include Flows as well?

If you click on your most recent Campaign and then the “Recipient Activity” tab, followed by clicking on the Bounced row, take a look at the reasons given.

Look at the reasons given and try to get a feel for whether they are mainly related to an issue caused by the recipient (eg, mailbox is full) or if the emails are being flagged by spam protection systems.

Let me know what you see and then we can look at next steps.

Thanks,

Ross