I have a conversation in which the teacher asked one of student's mother to sign up for volunteer work in the class. It's quite simple but I don't understand the implication of the mother, so I'm confused a little bit.
T: You start the volunteer work tomorrow, don't you?
M: Well, let me check the schedule. I guess I could just get the mail at night.
Would you mind explaining the sentence "I guess I could just get the mail at night" for me? The mother only gets email at night? Or something else?