For a while I received most of the new emails in Mailcow, but after some point all messages are delivered only to the old email provider. Sent emails were not delivered since the beginning.
In domain DNS settings MX record for the Mailcow email domain has the highest priority.
I can connect to accounts from email clients.
Messages are sent and received when they are exchanged between Mailcow email adresses.
What could be the reason of why email messages are not received from and sent to external adresses? I know that the provided information is not much but I will be more than happy to provide additional details if needed.