1.6.3 MARIADB edition.
Deployed with Downloadable installer
Linux version Oracle Linux Server release 8.8
Store mail accounts in MySQL
Web server Nginx
Manage mail accounts iRedAdmin

We use this server as an email forwarder more than anything else, it makes it simple for the users to send an email to a particular email address, I have a custom sieve script which takes any email to the given email address, updates the subject to a specific subject and then forwards the email on. We process around 5,000 emails a day.

However I'm unsure when this started, but it hasn't been creating the required subdirectories and objects in /var/vmail/vmail1 as it should - so for example I end up with the following error for a few accounts that I've created in the last 6 months.

/var/log/sieve.log:Apr 01 11:57:50 lda(rgtn_test@xxxxxx.co.uk)<2654903><nPQJLi76zGm3gigAbgcjHw>: Error: file_dotlock_open(/var/vmail/vmail1/xxxxxx.co.uk/r/g/t/rgtn_test-2026.01.29.11.58.04//.dovecot.lda-dupes) failed: No such file or directory

I will point out that this server hasn't had a restart in 981 days as well.

8GB RAM
4 CPU Cores
Hosted with a Cloud provider

Filesystem isn't full - though it is an attached block volume.

Filesystem                  Size  Used Avail Use% Mounted on
devtmpfs                    3.7G     0  3.7G   0% /dev
tmpfs                       3.8G  492K  3.8G   1% /dev/shm
tmpfs                       3.8G  394M  3.4G  11% /run
tmpfs                       3.8G     0  3.8G   0% /sys/fs/cgroup
/dev/mapper/ocivolume-root   36G   24G   12G  67% /
/dev/sda2                  1014M  792M  223M  79% /boot
/dev/sda1                   100M  5.1M   95M   6% /boot/efi
/dev/mapper/ocivolume-oled   10G  278M  9.8G   3% /var/oled
/dev/sdb1                   1.0T  9.4G 1015G   1% /var/vmail
tmpfs                       764M     0  764M   0% /run/user/988
tmpfs                       764M     0  764M   0% /run/user/1000
tmpfs                       764M     0  764M   0% /run/user/0

I also realise how far behind on versions this server is, and will be looking to update it, perhaps over a couple of bank holidays.

So anything I should look for in why it hasn't created the Maildir's?
How to resolve this, recreate the missing email directory objects?
Advice on the best way to get to the latest version? or is that 1 update at a time?

Cheers