implement only monitoring dns blocklists, without using them for incoming deliveries

so you can still know when someone has put you on their blocklist (which may
affect delivery), without using them.

also query dnsbls for our ips more often when we do more outgoing connections
for delivery: once every 100 messages, but at least 5 mins and at most 3 hours
since the previous check.
This commit is contained in:
Mechiel Lukkien
2024-03-05 16:30:38 +01:00
parent e0c36edb8f
commit 15e450df61
13 changed files with 305 additions and 83 deletions

View File

@ -241,9 +241,9 @@ another account can accept messages from the same sender.
### DNSBL
Mox can be configured to use an IP-based DNS blocklist (DNSBL). These are
Mox can be configured to use an IP-based DNS blocklist (DNSBL). In other software, these are
typically employed early in the SMTP session, to see if the remote IP is a
known spammer. If so, the delivery attempt is stopped early. Mox doesn't use
known spammer. If so, the delivery attempt is stopped immediately. Mox doesn't use
DNSBLs in its default installation. But if it is configured to use a DNSBL, it
is only invoked when the other reputation-based checks are not conclusive. For
these reasons:
@ -256,6 +256,9 @@ these reasons:
3. No leaking of IP addresses of mail servers a mox instance is communicating
with to the DNSBL operator.
Mox can also monitor DNSBLs for its own IPs only, without using those
blocklists to analyze incoming deliveries. The status is exported in metrics.
### Greylisting
Greylisting is a commonly implemented mechanism whereby the first delivery