It is possible that Gmail identifies notifications about document arrival notification and other notifications from VEP.SI as SPAM. In this case, follow the instructions https://support.google.com/mail/answer/1366858

Important: When you block a sender, even when you remove their emails from Spam, Gmail still automatically identifies their emails as spam.

If Gmail automatically sends emails from people you know to Spam, you can:

• Remove the email from Spam: After you remove the email, future emails from that sender won’t go to Spam.
• Add the sender to your contacts: When you add the sender to Google Contacts, Gmail stops sending their messages to Spam. Learn how to add, move, or import contacts.
• Create a filter: For specific senders, you can create a filter to label their email as important or another option that you choose. Learn how to create rules to filter your emails.