What are Alternatives to Personal Service?
Alternate Service can be service to an individual other than the intended recipient. In Ontario alternate / substitute service can be used in most actions where the intended recipient is not available at home. The document can be left with an adult person living in the same home, provided a copy is mailed to the recipient within a day. This affects the length of time the recipient has to file a response. Two examples of documents in Ontario that require Personal Service only are Notice of Divorce and a Subpoena.
Other Alternate service could be service to an individual by means other that handing it to the person the document was intended for. For example: Registered mail, email service, posting a copy to the recipient's door, social media posting.
These types of service are usually used when personal service cannot be effected and many require the court's approval to be used. Different courts, tribunals, and acts all have different rules. You have to rely on legal counsel or an experienced process server to provide advice on what you can do.
There are Civil Practice books that have dozens of pages of rules that may affect service. It is wise to seek counsel or rely on a professional process server to insure you are getting it right.