Why are e-mails from blocked senders not deleted on the server?

As a test, I add an e-mail address for my second account (which is not configured in Outlook Express, the only e-mail client on my host) to the Blocked list under the Authentication Database. That means any e-mails from that e-mail address should not get accepted. After sending an e-mail from this blocked sender, sure enough I do not see it show up in Outlook Express. So Comodo Antispam seems to be working.

I then go into the webmail interface for that account (the one that OE is polling for new messages). The supposedly blocked e-mail is still listed in my Inbox but is marked as read. So all CAS did was end up getting that e-mail marked as read so the e-mail client that polls for new messages only won’t see it; however, some e-mail clients will poll for all messages whether new or not. Also, when I use the webmail interface that supposedly blocked “test spam” still shows up in the Inbox list. It is marked as read but it is still listed. Why would I want to see all the blocked spams in my Inbox when using the webmail interface? Why isn’t CAS sending a “DEL” command for each blocked e-mail during the next mail poll?

I did 3 mail polls in Outlook Express. The first one gets CAS to retrieve a list of e-mails from my account and to send any challenges. The second poll was to retrieve any challenges. The third mail poll was to get any e-mails to Outlook Express for which challenges were received. It always takes TWO mail polls once a challenge response has been received: one for CAS to see it and another for CAS to let it pass through to the e-mail client. Because no challenges should have been sent for the blacklisted sender (I checked and no challenge was received), 3 mail polls should have been more than sufficient for CAS to update its Quarantined Database and to also issue a DEL command to the SMTP server to get rid of that spam up on the mail server in my mailbox there.

With SpamPal and its blacklist, and because it doesn’t do anything with the spam-tagged mails, all mails retrieved by my e-mail client get deleted when they get yanked during the mail session. That is, after issuing RETR to get the new e-mails, the e-mail client follows with a DELE command to get rid of it on the mail server (I do not enable the “keep mails on server” option). So the e-mail that was blacklisted by SpamPal ends up getting deleted in my e-mail client by its rules to manage spam and that e-mail also gets deleted on the mail server because the DELE command got issued against that mail item. That way, I don’t see the blocked e-mails in my e-mail client and I also don’t see them when using the webmail interface to my account.

However, all CAS does is prevent the e-mail from getting to the e-mail client. It does nothing in subsequent mail polls (or during the mail session when it see the e-mail from the blocked sender) to issue the DELE command to get rid of it in my mailbox on the server. Because CAS prevents the e-mail from reaching Outlook Express means that the e-mail client also cannot issue the DELE command (on a yanked e-mail that a rule ends up deleting locally).

Yes, I can see that CAS was developed to only keep out the blacklisted e-mails from getting to the locally executed e-mail client but I see no reason why CAS is not then following up by deleting that blocked e-mail on the server.

In my case, I use Thunderbird as email client and NONE of my emails are deleted on the server, blocked or allowed. Thunderbird will not retrieve ANY emails from the server henceforth until I got to web mail and delete the mail that was retrieved but not deleted.
Since posting this, I tried poling again and then it deleted the email

Is there perhaps a setting in Thunderbird that says how long read messages are to be kept on the server? (There is one in Outlook). I wonder how this interacts with CAS’s apparent use of the server account as a holding area…?

See also the recent thread about a supposed problem with Gmail, which actually seems to be related to a problem inb the way Thunderbird works with CAS:


Hi Vanguard_LH:

    CAS does not delete the e-mail until you want to delete it. There is two kinds of e-mails. One kind goes into you inbox, if your email client sets keeping copy inserver, it will not be deleted by CAS, if your e-mail client does not set keeping copy, CAS will remove it in next receiving it from server on this account; the other kind is quarantined e-mails, CAS will not remove it from server if email keep pending states, but if e-mail blocked, CAS will remove it in next receiving or quarantine time expired, which depends on your settings in CAS authentication database.