0

I have domain example.com and its mx properly configured. I have also an A entry intranet.example.com which points to my CMS. What I want is to have emails of the form user@intranet.example.com and I have to use a separate mail server than the one used for the example.com mail handling. My question is: 1.Should I just add an MX entry for in the example.com dns zone file like this: 

intranet      IN      MX      10      intranet-mailer.example.com

or create a whole separate intranet.example.com delegated subdomain, and put the MX there?

2.Is it safe to do both? 3.What about SPF in each case?

Thanks.

Paralife
  • 339
  • 1
  • 3
  • 10

1 Answers1

2

Unless there are other pressing reasons there's no need to create separate zones for MX records in subdomains, you can include the MX records in the main zone. That will also have a small benefit on the DNS lookup times.

 intranet          IN      TXT       "v=spf1 a mx -all"
 intranet          IN      MX  10    intranet-mailer.example.com 
 intranet-mailer   IN      A         10.98.87.65

Yes, either way you'll need to create a SPF record for the subdomain as well. e.g.

Be aware: often the intranet or internal subdomain actually is separate and restricted DNS zone, i.e. one that can only be resolved from within the internal network and by clients connected via VPN etc. Be careful when you put some of those records in your public DNS as well, you may end up with some unexpected results.

Community
  • 1
HBruijn
  • 72,524
  • 21
  • 127
  • 192