It stores mail in the MH mailbox format. Its Mail Transfer Agent provides intelligent email routing based on server or user mailbox location. Therefore, no USPS approved residential locking mailbox has secure outgoing mail. Mail, increased their mailbox storage in response. One week, the mail clerk overlooked his letter, explaining nothing was in Lee's mailbox. A traditional email hosting or per mailbox hosting. An MDA saves messages in the relevant mailbox format. When the message is consumed and removed from the mailbox the process resumes execution. This is to access the account and the encrypted mailbox and its private encryption key. There is also a stairway to the apartment above and a mailbox set with letters. Every unit typically gets its own mailbox with individual keys to it. Christian throws a copy of the letter in each apartment mailbox at night. One day Kya finds a letter in the mailbox. The key is used to unlock the mailbox containing the stolen cash. The man checks her apartment and sees that her mailbox filled with fliers.