- $l2m and $l2m->{-wq_nr_workers} = $mj // do {
- $mj = int($nproc * 0.75 + 0.5); # keep some CPU for git
+ $l2m and $l2m->{-wq_nr_workers} //= $mj // do {
+ # keep some CPU for git, and don't overload IMAP destinations
+ my $n = int($nproc * 0.75 + 0.5);
+ $self->{net} && $n > 4 ? 4 : $n;