mail_tracking problem the email send succesfully is maked as not send

[matteoopenf]

Module

The name of the module that has a bug.

Describe the bug

We found that if an e-mail is sent to a number of contacts and one of these addresses does not exist, all communication is marked as unsent when only a few did not receive the e-mail.
I would have expected only the email with error to be red

To Reproduce

Affected versions:

• 14.0
• 15.0 ?
• 16.0 ?

Steps to reproduce the behavior:

1. for istance create a invoice
2. put some follower and one of the follower with wrong addres
3. send email
4. all mail is marked as soft bounce

for istance

this mail is delivered and open is passed in softbounce

Expected behavior
I expect only email not really delivered generate a soft bounce not all.