▲ 2 r/Outlook
hello ppl🫡
im experiencing an issue with mail flow in Exchange. When sending emails (both from external domains and from our own domain), not all CC recipients receive the message. For example, if we send to 5 CC addresses, only 4 receive the email.
- The missing recipient does not appear in quarantine.
- We use ESET Cloud Office Security, and the message is not blocked there.
- In the Exchange mail flow logs, the email is shown as delivered to the other CC recipients, but not to the one that fails.
- This does not follow any specific sender pattern, it happens randomly.
Has anyone else seen this behavior recently, or is there a known issue with Exchange, mail flow or smt in April 2026?
u/Kuronojinsei — 14 days ago