Ken's Techno Tidbits

I use WordPress.com to host a number of web sites, and for simple stuff it’s great.

But I ran into a problem with keeping email separate, so I thought I’d share what I learned.

Here’s the background. I wanted to have http://bixolabs.com and http://www.bixolabs.com both wind up at the web site being hosted by WordPress.com. But I wanted to keep my email separate, versus using the GMail-only approach supported by WordPress.

According to WordPress documentation, you can’t do this. They say:

Changing the name servers will make any previously setup custom DNS records such as A, CNAME, or MX records stop working, and we do not have an option for you to create custom DNS records here. If you already have email configured on your domain, you must either switch to Custom Email with Google Apps or you can use a subdomain instead which doesn’t require changing the name servers.

This meant that I couldn’t just change my name server to WordPress, as they don’t support any customization.

But if I keep my own DNS configuration, then all I can do is use a CNAME record to map a subdomain to WordPress. And you can’t treat “www” as a subdomain.

So my first attempt was to configure my DNS record as follows:

• www -> [URL redirect] -> http://bixolabs.com
• @ -> [CNAME] -> bixolabs.wordpress.com
• @ -> [MX] -> <my hoster’s mail server IP address>

This worked pretty well. http://www.bixolabs.com got redirected to bixolabs.com, and bixolabs.com mapped to the bixolabs site at WordPress.com.

But the http://www.bixolabs.com redirect was a temp redirect (HTTP 302 status) not a permanent redirect (HTTP 301 status), so I was losing some SEO “juice” due to how Google and others interpret temp vs. perm redirects.

I fixed this by having my hoster set up their Apache server to do a permanent redirect, and changing the entry for www to point to the Apache server’s IP address.

But there was a bigger, hidden problem. Occasionally people would complain about getting email bounces, when they tried to reply to one of my emails. The reply-to address in my email would be ken@bixolabs.com, but the To: field in their reply would be set to ken@lb.wordpress.com.

Eventually I figured out the problem. It’s technically not valid to have both a CNAME and an MX DNS entry for the same domain (or sub-domain, I assume). If a mail client does a lookup on the reply-to domain, bixolabs.com has the canonical address of “lb.wordpress.com”, since the CNAME entry overrides the MX entry.

The fix for this involved three steps. First, I changed the MX entry in my DNS setup to use “mail”, not “@”. Then I changed my email client reply-to address to use mail.bixolabs.com, not just bixolabs.com. And finally, my hoster had to configure their mail server to recognize mail.bixolabs.com as a valid domain, not just bixolabs.com.