[Savannah-hackers-public] Delays in mail delivery by gnu.org mailing lists

[Eli Zaretskii]

Lately, mail delivery by gnu.org mailing lists intermittently suffers
from very long delays.  For example, currently emacs-devel and
help-gnu-emacs mail is delivered with delays between 45 minutes and
1.5 hours (based on admittedly small and potentially
non-representative sample).

This happens a lot during the last days.

What causes this?  Can this be improved?  TIA.

P.S. https://hostux.social/@fsfstatus is as usual not helpful.