External MailTip

Hi,

For this example we have our domains

domain.co.uk
domain.it

When sending emails to these domain we receive no External Mailtip Warning - Which is correct.

We have another domain associated with the company, but is not managed by us. When sending to the domain we receive the MailTip when sending to the domain

domain.fr 

Is it possible to set the External MailTip, to ignore this domain and not give a warning? 

Thank you in advance