Nice, so at least your messages sent to their SMTP servers will actually bounce instead of being silently dropped /s
Nah, no way they're getting rid of their M.C.-Escher-esque 'Forefront' mail-disappearance-machine-that-nobody-in-Microsoft-seems-to-understand-or-control, but, yeah, even their Internet-facing infrastructure seems unhappy:
451 4.3.2 Temporary server error. Please try again later ATTR2 [MI3PEPF00008486.eurprd02.prod.outlook.com 2026-11-12Txxxxxxxxxxxxxx]
Anything sent to my work or home Outlook email from gmail doesn't bounce back, and anything sent from those is still stuck in the outbox. Microsoft.
Normally if server down, smtp will wait a little while and try again.