An e-mail address that does not meet the default stup of an e-mail or an e-mail that no longer exists based on the domain name can be viewed via e-mail validation.
Click on 'your relations' and 'data scans'
Select the 'check e-mail addresses' button.
Examples of e-mail addresses that are not valid
This address is missing a dot between gmail and com
hotmail.co should be hotmail.com
The domain name does not exist
How do you correct a wrong address?
Correct the e-mail address in your DMS. The next that is also corrected in the Contact module.