Outlook send and receive problems

[#1]

I have security cameras that use Plusnet addresses to send emails to me at a) my postmaster plusnet address and b) my own domain address. About a week ago I stopped receiving the emails from the cameras to the postmaster plusnet address - they do not appear in the webmail box for postmaster nor are they being collected by Outlook,

I have had no notification that I have been migrated, and I haven't made any other changes.

I have now checked the various send/receive combinations and this is what I find:

Cameras sending direct to my domain address - no problem. The outgoing plusnet parameters set there are still working, 

Camera address sending from Webmail  to Postmaster - no problem, the message appears in the Postmaster webmail inbox AND is collected by Outlook.

Conversely, Postmaster sending from Webmail to my domain address is NOT appearing in my Outlook inbox.

Message sent from Postmaster in Outlook to a camera address produces an 550 (recipient rejected - relay denied) error report.

Message sent from my domain address in Outlook to either of the plusnet addresses is received OK in webmail but is not collected in Outlook.

I can't make any systematic sense of this - any ideas?

Thanks Margaret

[#2]

Correction  -

Postmaster sending from Webmail to my domain address IS appearing in my Outlook inbox. So Plusnet Webmail sending is working OK on both addresses.

Also sending from my domain address to either of the plusnet addresses ARE received OK both in webmail AND collected in Outlook.

So the outstanding error conditions are:

Sending from the camera itself to postmaster or to another camera address fails silently - nothing in the webmail inboxes and nothing collected by Outlook. Even though the cameras are sending fine to the domain address.

Sending from Postmaster in Outlook to a camera address produces an 550 (recipient rejected - relay denied) error report.

So the problem seems to be sending/receiving between plusnet addresses - not with Outlook at all.

Hoping support will pick this up.

[#3]

Tuesday 12:40hrs

Seems like everything is dead again.  Unable to access email either via webmail or Outlook....

[#4]

Looks like someone has hit a reset button...  all working again... until the next time