I'm running vCenter 6.7 w/ three host also running ESXI 6.7.
I had certain alerts send me email notifications (like if a host lost power) and for whatever reason it just stopped working. For testing proposes, I'm testing an alert when a VM powers off to send me and email notification. After powering ff the VM, it has yet to send me a successful email. I'm not sure if some updates has stopped this from happening or what. Is anyone else having this issue?
I've seemed to have lost that ability to have vCenter email notifications. Like I said, it was working in the past.
I do get other mail alerts from other apps like Veeam everyday, so I know the Office 365 email address or the SMTP server isn't the issue.
What am I missing in vCenter?
Look at the links in this post if they can be useful. Also try taking the test in ssh from vcenter.
Are there any firewalls between the vcenter network and the client where you receive the mail (port 25)?
Can you check the network connections (TCP/UDP) between the vCenter server and your Mail server? Maybe something prevent your E-Mail operations like firewall, or maybe it's because of a wrong/invalid settings for sending E-Maill (in alert definition) .... however please check the communication between the VC and MX, via running the tcpdump on the vcenter shell like these:
tcpdump -i eth0 tcp port 25 (SMTP default port, if you used)
tcpdump -i eth0 dst 220.127.116.11 (IP address of the Mail Server)