If you are unable to send an email from your Office Microsoft 365 account, make sure you have reached the daily limit.
...
You cannot send an email from your Office Microsoft 365 account
When you try to send an email, you receive the message "Your message cannot be sent because you have reached your daily limit for recipients."
...
Request a new LISTSERV mailing list (Morgantown campus, PSC or Tech) bysubmitting a WVU IT request
Request a new LISTSERV mailing list (HSC) by submitting a WVU IT request
For other email limitations, view the Exchange Online Limits information from MicrosoftMailing List Request.