Discourse needs to send notification emails. It’s easy to setup a local mail transfer agent to deliver your own emails, but the hard part is maintaining long-term deliverability. This can be a major headache, especially if the IP address of your server is placed on a spam blacklist. Therefore, some people prefer to outsource email delivery to a commercial service.
If you’d rather deliver your own email, leave the discourse_smtp_* options
at their default values and ansible-discourse will automatically install
Postfix and OpenDKIM for you. However, you must take the following four steps to
avoid getting marked as spam.
Add a PTR record for reverse DNS lookup that points to your domain name (eg,
discourse.example.com). Usually you need to ask your hosting company to do
this for you. Check that the PTR record is active with the host command.
Before the PTR record has been added, output looks like this:
$ host 89.16.185.202
202.185.16.89.in-addr.arpa domain name pointer 89-16-185-202.no-reverse-dns-set.bytemark.co.uk.After the PTR record has been added, output looks like this:
$ host 89.16.185.202
202.185.16.89.in-addr.arpa domain name pointer discourse.jamielinux.com.An SPF record specifies hosts that are authorized to send email from your domain. Consult the documentation for your domain registrar for instructions on how to add a DNS record. In zone file format, it looks like this:
; You should already have an A/AAAA record pointing to your server.
discourse.jamielinux.com. IN A 89.16.185.202
; This SPF record only allows email to be sent from the IP address
; specified by the A record (or AAAA).
discourse.jamielinux.com. IN TXT "v=spf1 a -all"
DMARC is a method of email authentication and tells mail servers what to do with emails that fail SPF and DKIM validation. Add a DNS TXT record like this:
; quarantine tells mail servers to mark affected messages as spam.
_dmarc.discourse.jamielinux.com. IN TXT “v=DMARC1; p=quarantine;”