Here is a photo showing how the front door to the building is blocked when the mailboxes are not locked and they fall open.

Call the post office. This is not a DPW problem.

@Laxer it's appropriate if it's violating building egress/fire codes, which it is. It is also appropriate to notify the PO.

Dear Laxer and Bill Ward - I agree the best contact might be the USPS, which is why I suggested considering a "US Postal Service" category. I see posts on Front Porch Forum with issues and questions about mail delivery. I think SeeClickFix might be a better place for Burlingtonians to log and track these and share information learned from visits and phone calls, even if the USPS doesn't agree to use SeeClickFix to respond as City departments do.
I and my neighbors have called the USPS many (more than 10) times for this issue in past years. However, if the USPS is usually closed when we return home after work and notice the issue, so we don't currently have a reliable way to communicate with the USPS. The hours of Elmwood Post Office (863-6033) are M-F 8am-5pm and Saturday 9-1pm; the Pine Street (658-0919) is open from M-F 10am-4pm and Saturday 9-1pm. Sometimes even when you call during these hours, no one answers the phone. An article in Seven Days (https://www.sevendaysvt.com/vermont/timely-mail-sunday-packages-can-burlingtons-acting-postmaster-deliver/Content?oid=2539781) was accurate at the time it was published. Charley McClintock was our mail carrier for years (until he retired) and our current mail carrier is also very good and conscientious, which is why it confusing that there are short stretches of time when our mailboxes are not consistently closed and locked.

Issue acknowledged.

The United States Postal Service (USPS) has been notified via email - they would be responsible for addressing this issue.

USPS notified - issue closed.