One question we are often asked is “Why there is no outgoing mail security on a locking mailbox?”

For residential curbside locking mailboxes, the USPS mandates that the mail carrier cannot be required to have a key to access your mailbox. That means that incoming mail is deposited through an incoming mail slot or bin, and outgoing mail bust be retrievable without a lock.

Outgoing Mail on Mail Boss Mailbox Models

On the curbside Mail Boss and Package Master, there is an outgoing mail tray that is revealed when you open the incoming mail door. On the curbside Mail Manager, there is an outgoing mail clip on the inside of the incoming mail bin. On the Wall Mount Townhouse and Metro, there is an outgoing mail clip that is revealed when you open the incoming mail door.

Should You Send Outgoing Mail from Your Mailbox?

Briefly, no. If you are sending checks, bill payments, or anything with sensitive information that can be used for identity theft, we always recommend bringing it to a blue USPS collection mailbox or directly to the post office. Better yet, use online bill pay. It’s more secure.

If you must send mail from your mailbox, DON’T PUT THE FLAG UP!

The flag is just signal to thieves that says “Hey, come steal my mail!”Replacement Flag

Unlike with traditional mailboxes, with locking mailboxes, the outgoing mail is in a separate area than the incoming mail, so the mail carrier will see it when depositing your incoming mail and take it regardless of whether you use the flag or not.

So, if you must use outgoing mail from your locking mailbox, whatever you do, don’t put the flag up!


  1. Jason on October 10, 2019 at 10:30 am

    As a postal worker….We hate the mailbox you are telling people to get especially if you are somebody that receives small packages and large envelopes. I have heard of carriers skipping houses with these boxes because things won’t fit in the slot like a normal box. Second DONT EVER TELL PEOPLE NOT TO PUT THEIR FLAG UP. … if you don’t put your flag up and on that day you don’t have mail. Because your flag isn’t up we won’t know to stop at your box and we will skip it. So in all this is the stupidest most annoying box for a mail carrier

    • Yaasmiyn on September 8, 2020 at 8:15 pm

      Some feedback from a consumer, I brought this mailbox because I am tired of the mail man jamming packages in normal box that don’t fit and damaging my goods.

    • Carl Durgen on September 26, 2020 at 12:12 pm

      So while the box may be annoying to you, it’s your job. We buy these boxes because they are far more secure. Don’t like it, go be a healthcare worker.

  2. Joseph S Taub on August 17, 2020 at 2:54 pm

    The flag seems not to matter on my route–or at least on my box. I am retired and don’t get a lot of incoming mail–except bills–so if I put a letter in my mailbox WITH the flag up, it still remains there UNTIL I GET a letter, sometimes for four or more days!!! I’ve also been treated to incoming mail just put on top of outgoing mail which was not picked up; and my favorite: TWO OUT OF THREE picked up but not the third!

    In their defense, the local Postmaster has called me a LIAR!!

  3. Rose Haskins on September 5, 2020 at 2:57 pm

    My next door neighbor like to leave the flag up. When they don’t use it at all
    What shall I do ?

  4. Rose Haskins on September 5, 2020 at 2:58 pm

    My next door neighbor leaves the flag up when they don’t use it
    What shall I do

    • Rose Haskins on September 5, 2020 at 3:02 pm

      My next door neighbor leaves their mail box up periodically at times
      When they don’t use it at all
      What shall I do
      Or who do I need to speak with

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