Under what circumstance can process servers serve documents via mail?

Serving documents via mail is permissible particularly when prior in-person attempts to serve the individual have been unsuccessful. This approach is outlined in New York’s Civil Practice Law and Rules (CPLR), which provides specific guidelines for serving papers in a manner that ensures due process while accommodating the practicalities of the process server's role.

When in-person service is not possible, mailing documents can be a viable alternative, especially if a server has made reasonable efforts to personally deliver the documents. This method becomes a backup option to ensure that the recipient still receives the legal documents they are entitled to be notified about.

The other scenarios provided, although they may intuitively seem reasonable, do not align with the legal stipulations governing service by mail. For example, a recipient's request for service by mail (the first option) might not suffice unless stipulated by law. Similarly, an inaccessible business address (the third option) or lacking a valid return address (the fourth option) do not inherently justify service by mail without prior unsuccessful attempts at personal service. Therefore, the focus is on ensuring that the recipient is appropriately notified while maintaining the integrity of the service process.