The process to which I refer was not created manually, it has a link to the original letter. If you hover over this icon in the process, then there will be information that the process was created from a letter.
At the moment there are letters in the system, but they cannot turn into a process, because the client is not defined and the system cannot determine on whose behalf to create the process. Go to the setting of automatic actions once a minute https://nautilus.crm-onebox.com/admin/auto/action/minute/edit/
and in the action Turn an email into a process and specify the setting "Author of processes, in case the contact is not defined "