Any chance you are running the flashmemory plugin?

Likely related. I can no longer run that plugin because it disrupts rsyslog and mail for me.

Uninstall the plugin and see if mail behavior returns to normal.

I'm having the same issue. Staring some time fairly recently, emails are sent only at reboot. And they are not being deleted from the outbox queue so at every reboot the same emails are sent, along with any additional ones queued up since the last reboot.

Gderf you say uninstall flashmemory but looking at the OMV docs it says flashmemory is installed automatically and that it is required.

1: I see no option to uninstall (which makes sense if it's a required part of the package), and

2: What to replace it with? If it's required then it seems like I needs something to take on the wear-leveling tasks it's providing.

Hostname
pimedia

Version
7.7.7-1 (Sandworm)

Processor
Raspberry Pi 4 Model B Rev 1.4

Kernel
Linux 6.12.25+rpt-rpi-v8

System time
Mon May 19 19:52:22 2025

Uptime
15 minutes

Quote from omv_user22

Gderf you say uninstall flashmemory but looking at the OMV docs it says flashmemory is installed automatically and that it is required.

Where in the docs i this stated?

omv7:omv7_plugins:flashmemory [omv-extras.org]

Quote

Summary

The FlashMemory Plugin was designed to make booting from USB thumbdrives and SD-cards feasible and a practical alternative to booting from a hard drive or SSD. In addition to the relative low cost, using USB thumbdrives enable easy OS backup options, quick recovery from boot drive failure and it saves a SATA port for a data storage drive.

This plugin is REQUIRED, for a flash media boot drive, or it will have a short life. For an in-depth explanation see; Why is the FlashMemory Plugin Required?

Restarting postfix unleashed a flood of emails. Now to see if that's a one-time thing or if it will continue to work

"This plugin is REQUIRED, for a flash media boot drive, or it will have a short life." This not the same thing as being required by OMV itself.

I know you have folder2ram (flashmemory) plugin, do you also have the antivirus plugin installed? If so, It's sounding a bit like it might be related to my issue with btrfs scrub. Check out /var/spool and /var/folder2ram/var/spool, specifically the mail folders.

Also systemctl status folder2ram_startup looking for any errors.

[edit]

disable clamav (antivirus) and see if mail problem is still there. if antivirus is enabled it impacts on flashmemory and stops it completing copies. Not sure if folder2ram is copying mail folders or not so this may be unrelated. ymmv

Quote from gderf

"This plugin is REQUIRED, for a flash media boot drive, or it will have a short life." This not the same thing as being required by OMV itself.

Splitting hairs. It doesn't matter to me if it's a dependency of OMV itself, or if OMV says it is required for a system to be reliable. The end result of either is that it is required, full stop.

Quote from greybeard

I know you have folder2ram (flashmemory) plugin, do you also have the antivirus plugin installed? If so, It's sounding a bit like it might be related to my issue with btrfs scrub. Check out /var/spool and /var/folder2ram/var/spool, specifically the mail folders.

Also systemctl status folder2ram_startup looking for any errors.

[edit]

disable clamav (antivirus) and see if mail problem is still there. if antivirus is enabled it impacts on flashmemory and stops it completing copies. Not sure if folder2ram is copying mail folders or not so this may be unrelated. ymmv

I don't have clamav installed so we can ignore that. For the record, the services I have running are flashmemory, docker, smb/cifs, and ssh

Quote from DaveOB

I know I'll get told this isn't the right way, but got tired of wasting time trying to solve it.
I simply added a scheduled task to restart postfix once an hour.
Not had an issue with it since. Been about 6 or 7 weeks like this.

Thanks. This appears to be an effective workaround

I've tried every single fix for this that has been suggested since I first reported the problem in the forum on September 11, 2024. None of them have worked. Removing the flash plugin was the only fix that did work. Maybe you will get lucky and one of the suggested fixes will work for you.

What I did was to replace my 32GB USB system drive with a 32GB SSD drive.

So far, kicking postfix every hour is working. Crude but effective

run the following:

ls -al /etc/logrotate.d

check the output for file ownership/group. They should all be root/root

If they aren't then flashmemory plugin fails on sync/boot/shutdown due to logrotate failing, the mail spool directory could be impacted indirectly.

Also see this thread Postfix Problems