Exchange 2010 to E5 migration causes automated emails to fail

[johncashF]

We have a very old on-prem Exchange 2010 that we are removing from our environment. We licensed everyone with E3 but email was still being routed through the on-prem Exchange with a Barracuda Firewall. Now we removed the Exchange, moved the MX record to O365 and upgraded the licensing to E5.  Everything went fine, surprisingly except the service accounts and SRS reporting even when addressed properly won't send automated email reports now.

Any ideas on what we could have missed?

[#2]

It depends on whether the service accounts are legitimate "users"/"mailbox". In some cases, additional reconfiguration is needed to be done on the tool generating report to use a different account, because virtual account is not the same as what you have in on-premise now.