[RFCI-Discuss] about FQDN for our smtp servers

[Jeff Pang]

Hello,lists,

I saw this statement in RFC2821:

3.6 Domains

   Only resolvable, fully-qualified, domain names (FQDNs) are permitted
   when domain names are used in SMTP.  In other words, names that can
   be resolved to MX RRs or A RRs (as discussed in section 5) are
   permitted, as are CNAME RRs whose targets can be resolved, in turn,
   to MX or A RRs.  Local nicknames or unqualified names MUST NOT be
   used.


I don't clearly know what is FQDN.Is it mean our SMTP server's A record?or ptr record?

For example,the IP of '220.181.12.14' is one of our smtp server,whose A record is:

 smtp.163.split.netease.com

and alias to:

 smtp.163.com

When this MTA connect to other site's MTA,it issue the HELO command as:

  HELO smtp.163.com

It use the alias as its domain.Does this breach the RFC?How can we resolve it?Thanks.

(btw: can we use the ptr record as our HELO domain? for example,for the host of '220.181.12.14',whose ptr record is 'm12-14.163.com',can we use it as HELO domain?)




--
Jeff Pang
NetEase AntiSpam Team
http://corp.netease.com