Hey Linda,
If you have changed the field "Opted Out" to "No" for a contact record and it is automatically changing to "Yes", this can be due to two reasons only:
1) Hard Bounce: The email address for this contact record is incorrect.
So, when you send them an email, it is being hard bounced by the server due to incorrect email address and the system is automatically opting them out.
2) Self Opt-out: It could be possible that you sent them an email and the person has clicked on the opt-out link again.
You can check the opt-out details for all the contact record by running a standard report in your account.
You can access the report under:
Contacts > Reporting > Contacts that Opted out > Run Report
This report would give you all the details like:
- Last Email Sent
- Opted out Date
- Opted out by (Self opt out/Hard Bounce)
- Email Name (From which the opt out action triggered)
- Activity name (Which even/campaign the email belongs to)
Hope this helps!
Regards
Ankita Gupta