I have a VPS server that I would like to get an SSL certificate for, and the CA needs an email address to verify that I own the domain. The options are: [email protected], [email protected], [email protected], and an address to @whoisguard.com.

The server runs CentOS 5, and all I have set up for email is sendmail. I don't have POP3 or IMAP. According to this Wikipedia article on Postmaster, it says that all SMTP servers support postmaster and it cites RFC 5321. Does sendmail conform to this? I tried sending a test mail to [email protected], but I don't know how to receive it on my server. Do I need to open up any ports?

I haven't gotten a message back saying that my test mail failed to send, so my server must have gotten it.

1 Answer 1


Take a look at /etc/aliases. Usually, postmaster is redirected to root; the question becomes who gets root's mail Best practice is to add an alias to route it to your email address (e.g. root: [email protected]), then sudo newaliases to install the new alias file.

  • I tried this. I checked /var/mail/root, and my Gmail account; I sent 4 or 5 emails, and I haven't gotten any of them. Do I need to setup any permissions to receive mail? /etc/mail/access for instance?
    – jonescb
    Commented Mar 13, 2011 at 0:09
  • Possibly, but first you need to know what's happening to the mail. Check /var/log/mail for error messages, and run mailq to see if the messages are "stuck" for some reason and why.
    – geekosaur
    Commented Mar 13, 2011 at 0:15
  • The mail log only has stuff from when I ran newaliases. mailq says the queue is empty.
    – jonescb
    Commented Mar 13, 2011 at 1:41
  • I think the problem is that I can't access port 25. I shut down iptables, and nmap says port 25 is filtered which probably means my VPS provider is blocking it.
    – jonescb
    Commented Mar 13, 2011 at 2:34

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