Notification SMTP undeliverable (bare line feed characters)

[Andi@AXS]

Hi there,

this forum helped me a lot in my journey so far with my Proxmox VE, so I am surprised, that I couldn't find a post about my problem.

I set up an email Notification with the type SMTP. The test notification works, and the one time a backup didn't work, it also sent a correct email.
Now I logged in to my sending Email account, and I saw a lot of rejected Email notifications.
Your message contains invalid characters (bare line feed characters) which the email servers at xxx.com don't support.
After reading a bit online, as far as I understand, this error comes from a line feed ... duh ... in the original message that could be used to inject a malformed message.
Then I checked the returned Email, and I think I found the culprit, the subject.

Subject: SMART error (OfflineUncorrectableSector) detected on host:
*hostname*

The Email path is PVE via SMTP → gmx.net → outlook.com → 1&1
1&1 (kundenserver.de) return the Email with this message:

550 5.6.11 SMTPSEND.BareLinefeedsAreIllegal; message contains
bare linefeeds, which cannot be sent via DATA and receiving
system does not support BDAT

I can't find where to configure the subject as I suspect, it is a configuration issue. (Or can I set a rule that replaces line feeds with whitespace or something similar?)
Also, I recon, 1&1 uses an old standard that does not support BDAT, which could be concerning?
If someone has a pointer for me on where to start, I would be very greatful!
In the meantime, I am going to check my drives ...


Thanks in advance!
Greetings Andi

 

[ubu]

I have the same Problem

 

[Lukas Wagner]

Subject: SMART error (OfflineUncorrectableSector) detected on host:
*hostname*

The Email path is PVE via SMTP → gmx.net → outlook.com → 1&1
1&1 (kundenserver.de) return the Email with this message:

550 5.6.11 SMTPSEND.BareLinefeedsAreIllegal; message contains
bare linefeeds, which cannot be sent via DATA and receiving
system does not support BDAT

So, this seems to be an email that is not directly sent out by PVE, but by smartd, going through proxmox-mail-forward and out through
the SMTP endpoint.

I'll try to look into this when I find the time

 

[Andi@AXS]

So, this seems to be an email that is not directly sent out by PVE, but by smartd, going through proxmox-mail-forward and out through
the SMTP endpoint.

I'll try to look into this when I find the time

Hi Lukas, sorry for beeing unresponsive for so long.
I fixed it!

Yes, you are right, the Email is triggerd from smartd, and somewhere in the message there will be a linefeed.
I think the proxmox mail service should prevent this befor sending, but I can imagine this is a problem of my constellation, maby.

I found these instructions:
Setting up SMART Monitoring in Proxmox

So the solution was to edit the default smart scan and extend it, now I get better alarms and they reach my inbox.
Maby the default smartd.conf from proxmox can be update to something like this.

Sidenote.
I am running Truenas in proxmox and some disks are assigned to Truenas, this has to be thought of when configuring smartd, as proxmox can not read the smartstatus of the drive and you get the error "unable to open ATA device".

Thanx to "naturalborncoder"