Our Zlien account was originally set up to automatically change the owner’s information without notifying us. Under this setting, there was no process to catch scenarios when our customer turned out to be the Architect or General Contractor, which then changes our mailing requirement. This issue happened more often than not over 2.5 months, and around 80 preliminary notices were sent without the proper mailing requirement fulfilled. We have now changed the setting, rectifying the issue going forward. My question is, however, should we resend these notices that are now outside of the 20-day period? Keep in mind, Zlien sends all notices, certified as well as USPS, with a tracking number. It is my understanding, that based on the Zlien process, the only difference between the certified mail and USPS is the signature. With that said, can the certified mailing requirement be satisfied with a tracking number sent via USPS mail? Or does it have to be labeled certified? Does the law require a signature?