I have an email to be sent out from Marketo. All the leads of the email list were imported (synced) from SalesForce to Marketo. If a recipient unsubscribes or if the recipient's email is hard-bounced, would that information be also synced to SalesForce? In another words, whatever changes happen to the email status of a lead, would that info also be synced to SF?
As long as you have Unsubscribe field synced to Salesforce, as soon as someone unsubscribes or an email hard bounces, you'll see that person Unsubscribed in SFDC. To check if this is the case, go to Admin -> Field Management -> Search Unsubscribed on right hand side and check CRM Field Map is mapped to a Salesforce Lead and Contact field.
Unsubscribed=Email Opt Out at all times.
So yes, this is automatic.
Hard Bounced, however, is not necessarily automatic. You can sync it from Email Invalid to X or Hard Bounces (Email Bounces) can trigger a data value change of your choice.
Please remember that Hard Bounces are NOT always set to Email Invalid=T. You need to setup this system.
Can you think of any possible reasons why Unsubscribe would not be automatically mapping to Email Opt Out fields in Salesforce? I sent an email earlier today and got 8 unsubscribes, none of whom have that box checked in Salesforce as of a few minutes ago...
I would firstly check if the field on your unsubscribe form actually links the unsubscribe fields in Salesforce, in Field Management mine looks like this: