In #2991533: Don't send messages when site is in maintenance mode (offline), we disabled sending messages when the site was configured to be in maintenance mode. However, we should also disable sending messages when the site is installing or updating, during which operations we can easily detect this because the MAINTENANCE_MODE constant is defined.

You can see many examples of this in the repo:

https://git.drupalcode.org/search?utf8=%E2%9C%93&search=MAINTENANCE_MODE...

Comments

joelstein created an issue. See original summary.

joelstein’s picture

This should do the trick.