Question How to bypass/disable spam folder (Dovecot) when DMARC = quarantine?

[King555]

Server operating system version

Ubuntu 18.04.6 LTS x64

Plesk version and microupdate number

Plesk Obsidian 18.0.[latest] web admin edition

I use Dovecot as my mail server with Plesk and I configured all mail accounts in a way that spam messages get marked as spam (adding something to the subject) and then they are delivered normally.

Now I found out that this only applies to mails with a defined score by SpamAssassin. But when a mail is marked as spam because of a DMARC policy (p=quarantine), it is put to the spam folder, not to the inbox (I guess SpamAssassin plays no role in this case).

I fetch my mails via POP3 and so I never see that mails are in the spam folder.

Is there any way to bypass the spam folder? Or can I disable it? I already tried to set a Roundcube filter rule for it, but it seems to be a too complex problem for those filters.

 

[scsa20]

So first question is, is this happening within web mail as well or just the client? Some clients would just honor whatever the header says regardless of settings on the web server.

If it's happening on the web mail, then you could go to the email in plesk, go to spam filter, and turn off spam filtering all together for the email address. But usually when an email is marked as spam because of a DMARC policy of quarantine, then it would always go to the spam folder if the other party's email server is not set properly to not flag it as such (since DMARC is used primary to prevent spoofing, aka says who they say they are). If this is not the behaver you want and want those emails to go to your inbox anyways but want the reporting, then change the policy to none.

 

[King555]

Thanks for your reply.

I'm not sure whether I understand your first question. This happens on server level. I think it's completely client-independent. The mail arrives and is directly put into the spam folder, no client involved at this time.

Turning off the spam filter is no option. I need it. But spam should be marked with an addition to the subject, as I set it in the spam filter options in Plesk, and then be delievered to the inbox.

And concerning changing the policy to none: it's not my policy, but of the sender (of the domain, which is "used" by the sender). When the domain says "reject", it's completely OK if mails are rejected. But it does not make sense in my case that the mails are moved to spam, because I don't look in the spam folder. And this could also lead to a large mail account, when the spam folder is not emptied automatically (I don't know whether this is the case).

when an email is marked as spam because of a DMARC policy of quarantine, then it would always go to the spam folder

Yes, that's the problem. I think there is a DMARC spam filter, which is not SpamAssassin, which cannot be configured like SA (i.e. with the option what to do with spam). And that's why I'm searching for a work-around/an alternative.

 

[scsa20]

As I mention, if everything else is lined up then DMARC is doing what it's doing. The other party will need to fix their email/DNS settings because it's failing the DMARC check which is causing it to go to the spam folder. The only other way around it is to change the policy to none like I've mention (or use IMAP instead of POP3 for your client, I usually prefer to use IMAP anyways since it allows you to get your emails from multiple devices easily).

 

[King555]

The other party will need to fix their email/DNS settings

The other party in this case is a spammer, whose mails are correctly regarded as spam by DMARC.

Maybe I was misunderstood. The DMARC filter works perfectly on both sides (sender and receiver). My question is, is there any way to configure the DMARC spam filter like I can configure the SpamAssassin filter? At this moment it seems there is no way.

 

[scsa20]

As I've mention, no, any emails flagged as spam by DMARC where your policy is set to quarantine will always goes to spam. Only work around is to A) set the DMARC policy to none or B) Use IMAP so you can access the spam folder as well.

 

[King555]

Only work around is to A) set the DMARC policy to none

OK, maybe I completely misunderstood what DMARC/SPF/DKIM is. I thought it's like this: When I get a mail from a spam server, but it claims to be from @microsoft.com, my server checks Microsoft's server. Microsoft says, only microsoft.com can send mails in the name of microsoft.com. So my server asks what Microsoft's DMARC DNS entry is. If it's quarantine, my server quarantines the mail, if it's reject, my server rejects the mail.

But if I understand you correctly, the mail is quarantined when my policy is quarantine. But the thing is, my policy is set to reject, but mails go to spam, when the senders policy is quarantine. Actually I'm 100% sure that it won't help changing the policy on my side.

IMAP is not an option for me, because I don't trust myself as a mail provider.

Thanks for your help so far. Maybe someone else has any idea on how to solve this problem. Yes, the mails go to spam, but maybe it's possible to configure Dovecot that this folder is kind of deactivated or there is any scripting possibility to auto-move every spam message to inbox. Some "inofficial" way.

 

[michela.d]

@King555 I have the same problem, have you found a solution?

 

[King555]

@michela.d
No, not yet. And I think it's not possible. Maybe it needs a feature request for Plesk.