Hints on running a well-configured outgoing mail server. permalink
If you do not have a static IP address, use your ISP's
mail relay (smarthost).
Make sure that there is a reverse DNS (PTR) record for your
IP address. Make sure that it is not generic (e.g. wylie.me.uk,
rather than client-12-34-56-78.adsl.example.org). You will need
to contact your ISP to do this.
Make sure that doing a PTR lookup, then doing an A lookup on that domain name gives the original IP address, e.g.
$ host 188.8.131.52 184.108.40.206.in-addr.arpa domain name pointer wylie.me.uk. $ host wylie.me.uk wylie.me.uk has address 220.127.116.11
Get your ISP to SWIP your IP allocation, so that a whois lookup shows
that it is allocated to you.
Make sure that your ISP has not listed your IP address as dynamic with
any DNSBL, e.g. dul.dnsbl.sorbs.net. If necessary, get your ISP to contact
the DNSBL maintainers and ask for your IP address to be delisted.
- Make sure that your HELO/EHLO string is a FQDN (Fully Qualified Domain Name), e.g. "wylie.me.uk", rather than "NTSERVER", as required by RFC 2821 section 18.104.22.168
Spamhaus reverse DNS
Spamhaus Dynamic IP lists
Yahoo mail help
AOL Technical Standards for E-mail Delivery
AOL Reverse DNS
Messaging Anti-Abuse Working Group Sender Best Communications Practices