With this configuration if the user attempts to send spam or a
virus, the message will be quarantined and the user will be
notified of the issue.
MR !9
Service amavis even though part of group vmail who has mark 770
on '/var/spool/spamassassin', can't write lockfile to do a bayes
check.
Set '/var/spool/spamassassin' mask to be `777` with owner
`debian-spamd:vmail` recursive. so that amavis bayes check works.
MR !9
Sieve extensions set to:
-vacation
Remove vaction extension as this has the potential to leak to
external users. this could be re-enabled if it could be blocked
from leaving the server and only being available within the
same domain
-enotify
Remove enotify extension as this has the potential to leak to
external users. this could be re-enabled if it could be blocked
from leaving the server and only being available within the
same domain
-editheader
editheader disabled, as the user should not be able to edit
message headers as this could remove message validity.
imap4flags
Enable imap4flags so that the user can flag messages as they
desire.
MR !9
used https://ssl-config.mozilla.org/ to generate recommended
ciphers config for dovecot and postfix.
postfix set to use medium ciphers due to possibility of smtp
servers not being updated to latest.
MR !9
Mail quota was not visible in Thunderbird. bug was havinf two
`quota =` rules. adjusted to `quota2=` for shared quota to diplay,
however, had no effect in display shared quota.
Disabled shared in the meantime.
MR !7
Check the users quota before accepting the mail for delivery.
If the user belongs to the server, the user wont send the message,
nor save it for it only to be rejected at a later stage.
Current rules and order as follows:
1. reject_non_fqdn_recipient
Require recipient to be in FQDN format so the message can
be routed.
2. reject_unknown_recipient_domain
Prevent mail from being sent to a random location that can't
be found.
3. check_policy_service,unix:private/quota
If the mail is for a local user and their mailbox is full, reject
the mail.
This allows the sender not to recieve a bounce message for
a message that wasn't actually sent.
4. permit_sasl_authenticated
A user of the mail server can send E-Mail to anyone as long as
it passes the filters above.
5. reject
Reject any further mail, as they clearly are not a user of the
mail server.
MR !7
Filter mail based on recipient restrictions. default is to filter then
reject the remaining.
This is a default rule and submission requires it's own rule specified.
rules and order as follows:
1. permit_mynetworks
Allow local mail host to send to whomever.
2. reject_non_fqdn_recipient
must use a FQDN so that the recipient can be identified.
3. reject_unknown_recipient_domain
Only accept mail for the domains we host.
4. reject_unauth_destination
reject mail for domains we don't host and before any policy
checks are done. This prevents additional processes from
spawning that would otherwise be unused.
5. check_policy_service,unix:private/policyd-spf
bounce the mail that fails spf check. likely to be a non-smtp
server.
6. check_policy_service unix:private/quota
Check the recipients quota before delivery. if fails, bounce
the mail.
7. permit_auth_destination
Only accept mail for domains we host. This rule placed after
the bounces, so that filtering can be done first.
8. reject
Hard reject as the recipient doesn't belong to this host.
MR !7
There is no requirement to open an additional port so that postfix can
can check the dovecot quota.
The socket is created in postfix's service directory with dovecot as the
owner and vmail as the group. setting it this way enables ls command to
display who the owner is for debugging purposes.
Postfix is a member of group vmail.
MR !7
Default config is for domain example.org, which
is the testing domain.
User will be required to customise '90-dkim' with thier
own domain configuration, including generating dkim signing certificates.
MR !2
