No Activity Emails

All of a sudden we are getting no activity emails. When someone uploads a file to an upload only share, the user gets an email notification. This has been the case until recently, but no changes were made.

The SMTP test message works. I can see the test message hits my upstream postfix server and then O365. When I upload a file, no email is sent. Nothing shows up in postfix and nothing in O365. I am using a cron job for this
* * * * * /bin/php74 /var/www/html/nextcloud/occ activity:send-mails
and the cron logs look good.

Jan 22 12:54:01 ip-192-168-20-101 CROND[17327]: (apache) CMD (/bin/php74 /var/www/html/nextcloud/occ activity:send-mails)
Jan 22 12:55:01 ip-192-168-20-101 CROND[17348]: (apache) CMD (/bin/php74 /var/www/html/nextcloud/occ activity:send-mails)

Looking at the local server mail log, I do see the following entries. Does nextcloud use local postfix and would it be sending anything to root?

Jan 22 13:06:02 ip-192-168-20-101 postfix/cleanup[17631]: 56058401147: message-id=<>
Jan 22 13:06:02 ip-192-168-20-101 postfix/bounce[17617]: 4FA5A400DAE: sender non-delivery notification: 56058401147
Jan 22 13:06:02 ip-192-168-20-101 postfix/qmgr[1084]: 56058401147: from=<>, size=3218, nrcpt=1 (queue active)
Jan 22 13:06:02 ip-192-168-20-101 postfix/qmgr[1084]: 4FA5A400DAE: removed
Jan 22 13:06:02 ip-192-168-20-101 postfix/local[17614]: 56058401147: to=<>, orig_to=<>, relay=local, delay=0.01, delays=0/0/0/0.01, dsn=5.2.2, status=bounced (cannot update mailbox /var/mail/root for user root. error writing message: File too large)
Jan 22 13:06:02 ip-192-168-20-101 postfix/qmgr[1084]: 56058401147: removed

Never mind. I was using a share link that went to another DL that I was not testing. Emails are working fine.