I haven't received notifications for two days now, and after a lot of digging, I found the following helpful information in one of LJs quadrillion of maintenance communities:
Spamhaus has blocked the following from LJ:
livejournal.com ,
208.93.0.128 and 208.93.0.48 ,
lj_notify@livejournal.com,
webmaster@livejournal.com,
do-not-reply@livejournal.com
Spamhaus.org states that these sites are now part of a bot net, and that the LJ email servers are infected with the Gurm spambot.
In short: any mail provider which uses the Spamhaus.org spam filters (means: a lot of providers) doesn't forward LJ's mails to you. Not until LJ gets its act together, boots the bots and gets the all-clear from Spamhaus.org. Which, knowing LJ's glacial working speed, will be around Christmas 2023.
I usually crosspost from DW, so can I just say that I HATE the new LJ "new entry" page. Hate, hate, hate.
More negativity to follow soon.