I encountered an interesting phenomenon this week concerning email that started me thinking about ramifications this had on overall email distribution for professionals like us. I have a few different email accounts with different domains that all forward to my one email account. It is not an optimum way of doing things but it works for the way I work. Awhile back I stopped receiving the forwarded emails from my custom domain hosting with Google Apps. The emails sent to this custom domain account did not bounce, and no other error indications where happening, the emails were just not seemly being forwarded. After scouring the internet for hours no one had a really good explanation...but then I thought, SPF record. When I forward emails from the custom domain on the Google Apps account, in essense, Google Apps becomes an SMTP server for that custom domain. If that is the case, then the receiving SMTP server is going to check to see if the Google Apps account has "authority" to send on behalf of my custom domain (using the SPF record), and if not, the email will be dropped. Well, I created an SPF record in the DNS for the custom domain, waited a few hours for it to propagate, and bam the forwarded emails started showing up. Here is the DNS TXT record entry I made in GoDaddy:
So, I suppose the moral of the story is if you are sending emails for a specific domain, make sure you give authority to this SMTP server or servers sending those so that the destination SMTP server will not reject them. Remember, the destination SMTP server is not obligate to return a bounce saying the email did not make it. With all the effort we do to make clean lists and work in a professional scenario, it is a shame if something as simple as this hinders your efforts.