> Also, with clamav-milter and sendmail. I see that the headers of quarantined messages go to /var/spool/mqueue with root:smmsp owner/group permissions and the header of the email starts with hf whilst the body of the message starts with df. So the message in question looks like this:
> -rw------- 1 root smmsp 10050 Apr 12 09:40 hf13CDdtaZ2926176
> -rw------- 1 root smmsp 100157 Apr 12 09:39 df13CDdtaZ2926176
>
> To release the message how does one find the queue_id to use the sendmail -qI command?

I just checked out our quarantine to see what you were talking about and found a couple of ads in there.
Forwarded off a sample to Micah, but it looks like there are some very phishy looking links in the samples I have.
HTML link: americanexpress.com/rewards-info
Actual underlying link: https://urldefense.proofpoint.com/v2/url?u=https-3A__click.o.delta.com_u_-3Fqs-3D1568763c78f67b6cdcd44df9cfac10c6bdd8a68c567c4d04238da45d4092cc1adeef2f53a3a8c4248f7140f92bd80fb33b830537983d2ad07ed440f137dd0226&d=DwICAg&c=aqMfXOEvEJQh2iQMCb7Wy8l0sPnURkcqADc2guUW8IM&r=X0jL9y0sL4r4iU_qVtR3lLNo4tOL1ry_m7-psV3GejY&m=P8yJim8mHfh9YWQcm2zQMPSq7pKr5iHpgTAzY5BA-xw&s=PC29G4XeTV8m9J0VpeSVtq9inSWRkSuL-sm_4k0mvpA&e=

If you ask me, that deserves to be quarantined.

Yes I agree but it's a bit subjective.

For Sendmail, it should be something like "sendmail -q" I would definitely look it up in the man pages, as I've been using postfix and exim now for awhile.

Well from http://www.postfix.org/postqueue.1.html

-i queue_id

Schedule immediate delivery of deferred mail with the specified queue ID.
This option implements the traditional sendmail -qI command, by contacting the flush(8) server.

But that (sendmail -qI) doesn't appear to unquarantine anything. My question is what does "queue_id" refer to?

And from a user's blog (with translation on)https://nauwg3k7ped5ecgcukpptbgr6e-jj2cvlaia66be-www-usebox-net.translate.goog/jjm/sendmail/

Processing the queue
If we remember the Sendmail execution line, we will see that it is indicated by means of -q30m processing the messages stored in the queue every 30 minutes. You can force the process by:
# sendmail -q
If we wanted to process a specific message we would use -qI _Q-ID_, for example:
# sendmail -qI hB8HQQhK013863
Or indicating the sender with -qS _remitente_:
# sendmail -qS '<reidrac@mydomain.com>'
Or indicating one of the recipients with -qR _destinatario_:
# sendmail -qR '<nouser@domain.without-mail.com>'

So I still don't know what "queue_id" is.