What part of speech is mail?

"Mail" can be a few different parts of speech, depending on how it's used:

* Noun: This is the most common usage. It refers to the system of delivering letters and packages, or to the letters and packages themselves.

* Example: "I checked the mail this morning."

* Verb: This is less common, but it means to send something by post.

* Example: "I mailed the package yesterday."

So, the specific part of speech depends on the context of the sentence.