The USPTO typically does not proactively notify existing trademark holders when a new trademark application is filed. It is the responsibility of trademark owners to monitor the marketplace for potential infringements and file appropriate opposition or cancellation proceedings if they believe their rights are being violated.
During the examination process, the USPTO examiner reviews the application and conducts a search for conflicting trademarks. If the examiner identifies a potential conflict with an existing mark, they may issue an office action raising objections or requesting additional information. In some cases, the USPTO may also issue a notice of publication, allowing existing trademark owners to oppose the registration of a new mark within a specified period.
It's important to note that the USPTO's search is limited to registered trademarks and pending applications on record. It does not cover unregistered trademarks or common law rights that may exist in the marketplace. Therefore, trademark owners should consider monitoring the marketplace and relevant databases for potential infringements and take appropriate action if necessary.