Technically, yes but you should use caution when doing so. The undeliverable status of a contact is a system built method to prevent sending to known bad data.
If you reset this status on a contact, you're accepting potential deliverability issues further down the line if the contact is still 'bad'.
Navigate to GatorMail > Audience > Contacts. Find your contact and look for the field called CRM_Pers_Undeliverable - 0 = deliverable, 1 = undeliverable. You can edit the status by using the pencil icon on the right hand side.