RE: Send emails through dynamics
Hello Javitm,
Could you please check the status of the email record.

if Status Reason shows "Pending Send" then you'd require to make sure mailbox is active for the CRM. You can check follow the steps as mentioned below.
You'd require System Administrator access to activate mailbox.
*Click Settings Button (top right) & Click Advanced Settings

Navigate to Mail Configuration

Open Mailbox record. If it is not listed in the view then you can change the view form My Active Mailboxes to Active Mailboxes

Check & Verify if Test Run Status, Incoming Email Status & Outgoing Email Status fields show Success. If not then open the Mailbox record.
Verify Incoming Email, Outgoing Email & Appointment, Contact and Tasks fields are set to "Server-Side Synchronization or Email Router"
Click Approve Email button and then Click Test & Enable Mailbox. (system will generate mailbox connection email to the mailbox user)

As soon mailbox is active, system will start releasing emails from Dynamics App.
Hopefully, the issue will be resolved.
Let me know if you have any questions.
Thanks,
Adnan