I've built a custom contac checkboxt field which just reads "inactive" which users select if the contact leaves the account. What I'd like to do is whenever that box is selected the "emailoptout" checkbox is also automatically selected.

I'm sure this can be done in validation or trigger, but I don't have much experience using those tools. Can someone help me get started on that?

I have a chunk of about 300 unresolved items that I would like to resolve using dataloader. This is my thought process on how this could work.

Download all of my unresolved items
Download all of my contacts

Match up the unresolved items to their corresponding Contact's SF ID.
Then re upload them to SF.

However I'm not sure how to do that last step. What route would I take to attach the unresolved item to a contact? Can someone help me with the parameters of that upload process?

I've built a custom contac checkboxt field which just reads "inactive" which users select if the contact leaves the account. What I'd like to do is whenever that box is selected the "emailoptout" checkbox is also automatically selected.

I'm sure this can be done in validation or trigger, but I don't have much experience using those tools. Can someone help me get started on that?

I have a chunk of about 300 unresolved items that I would like to resolve using dataloader. This is my thought process on how this could work.

Download all of my unresolved items
Download all of my contacts

Match up the unresolved items to their corresponding Contact's SF ID.
Then re upload them to SF.

However I'm not sure how to do that last step. What route would I take to attach the unresolved item to a contact? Can someone help me with the parameters of that upload process?