Scheduled Report shows successful status; but Mail...

System Overview:

Using SAP Business Objects 4.3 SP3

We recently switched to using a mail forwarding service SendGrid which has a 20mg limit on SMTP emails.  For the most part this has worked fine but there are a few schedules which have reports generated greater than 20mg in size.  Such schedules are failing to make it to their recipient; yet the schedule shows success.  It appears this is a hard limit within SendGrid that we can't configure.  I wouldn't mind but I would have expected the BO schedule to report failed; instead the schedule returns success!  Why?

I found KBA 1778797 Email recipient does not receive report but the instance status is "Success"

This KBA indicates because the relay/mail server "accepted responsibility for delivery of the message" BOBJ's responsibility has ended; thus job status is success. 

However, SendGrid testing using telnet shows it's not accepting responsibility.  it immediately returns an error:  "Mailbox unavailable.  The server response was: error reading data, max message size exceeded."  

I'm confident there's a gap here I'm missing but I'm not technical enough to see it. 

Could it be that SendGrid receives the email message.  sends an Acknowledgement back to BOBJ which BOBJ interprets as "I got it" and BOBJ moves on?  But then SendGrid does a process sees it violates rules and sends a message back which BOBJ ignores? 

To prove this out I created two reports one which is under 20mg (barely) one over 20mg (23).  These reports run daily.  I always receive the one less than 20mg.  The 23mg one has yet to get to me.  Both show status "Success"

When I use telnet to connect to the mail relay and generate a message to send, it returns an error message indicating the message is not accepted by the Mail server because it's too big.  I don't get any other acknowledgement..  So to me there's only one message from SendGrid... I reject your mail... so why does BOBJ show success? 

Does KBA 1778797 apply here? Do I need to open a ticket with SAP for investigation or is this a influence request to better handle errors/warnings from the mail servers when sending messages?   This appears to be a GAP in the process of handling email destinations I wasn't expecting to encounter.

Note: I have no access to our Server logs (they are administrated by a 3rd party) I have no access to mail server or relay (they are administrated by a different group).