All Clients/users from a company not receiving email notifications/updates for Support tickets?

[Sanskriti Ramtek]

One of our Client company user mentioned that none of their employees are receiving email notifications of the support ticket they have raised on the Jira Portal. Why could this be at a company level? Please advise.

[Sanskriti Ramtek · Accepted solution]

The issue has been resolved. We raised a ticket with Atlassian and learnt that the users were on our suppression list for some reason. They removed from the suppression list post which the client started receiving notifications normally again. They also ran a clear on the whole domain to check if any other users were being affected.
We were also recommended to tell the customer to whitelist the outbound notification ips to make sure that the emails aren't bouncing. If notifications fail to arrive at the destination for some reason, the email will be put on a suppression list to avoid sending email being put on a blocklist.