My address with you is coming up as invalid
This may happen if the website you're using to register your mailing address is being too strict with address verification and is not recognizing the mailbox number following the address as valid.There are a few ways to get around the situation which you can try:
If the site allows you to enter a line 2 for the shipping address, you can put the mailbox information in the second line.
In the event that it doesn't allow you to enter any specific info and there are simply no other options, then only enter the address without your mailbox number.
If you choose this secondary option, it is very important that the name you use matches a recipient in your mailbox. When we receive mail without a mailbox number, we will search the recipient name to see if there's a unique match. We do not recommend this method as it may delay mail from showing up in your mailbox sooner, but if this is the only way, then it's workable.
Usually option 1 works when you're on a website.