REST API misleading/useless responses?

I’m trying to send small files to computer mailboxes using REST API (ie. POST /api/mailbox/{computer_id}). The files are pretty small about 8kB each and I’m sending them in the batch. The problem is that BigFix server responds with confirmation ie. return code is 200 and the XML I get back looks like:

<BESAPI xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="BESAPI.xsd">
<ComputerMailboxFile Resource="https://mybigfixserver/api/mailbox/{computer_id}/9759">
	<Name>small_file.tar.gz</Name>
	<ID>9759</ID>
	<SHA1>aea6e652cb81ee4fa99a08ff130fb917440c16bf</SHA1>
	<Size>8462</Size>
	<Timestamp>Fri, 16 Sep 2022 14:33:37 +0000</Timestamp>
</ComputerMailboxFile></BESAPI>

so I would expect that this really means that the server received the file for the mailbox but then when I try to check the mailbox on that computer I see that there is nothing and I have to re-run the batch two or three times to be sure the files are REALLY delivered. I have tried to put some timeout between the requests just to make sure the server is able to cope with the batch of requests and it seems that it has some impact but still it is not 100% proof even when I set just 4 requests per minute.

Can anyone bring some insight into this? Why the heck is BigFix server sending successful response when it does not actually create resource at all?!

So far my only workaround is to run few iterations and check if the resource for the computer was really created using REST API and if not add it to next batch and run it again till everything is created.

How are you checking for the client file? Are you checking on the client itself, or querying REST again?

After the server has the mailbox file, it still needs to propagate a new client site and the client has to gather the site update before the file is visible to the client.

I’m checking through REST API.

It seems I have found the reason. I was not aware that mailbox is treated as any other site file so when the file name is the same (but different content) then the file is removed from mailbox of the first machine on which it was delivered and delivered to the last one.