I frequently get asked to troubleshoot computer problems. A friend asked me to help with email. I was simply told that there was trouble with email rather than a specific problem. Here are some of the things I checked to get to the root of the problem.
MX Records (Receiving Problem)
Verify your MX records at mxtoolbox.com.
http://mxtoolbox.com/SuperTool.aspx?action=mx%3asmartfile.com&run=toolpage
These records should point to the servers that are set up to handle your email. A problem I once saw here is that MX records were configured to send emails to two different servers. One of these servers did not have the user set up that was having problems.
You may need to do a second check on the server where you website is hosted if your email is hosted elsewhere. A common problem with website hosting is that the website server thought it was responsible for email also. This resulted in contact forms appearing not to send email. They did send it, but they sent it to a local mail-server.
SPF Records (Sending Problem)
Verify your SPF records at mxtoolbox.com.
http://mxtoolbox.com/SuperTool.aspx?action=spf%3asmartfile.com&run=toolpage
Note the ip4 and include records. ip4 records will identify servers that are allowed to send email from your domain. Ensure these are all servers that you still use. The include records will look up the spf for the included domain. The included domain can include other domains.
Blacklist Check (Sending Problem)
Verify your domain isn’t blacklisted.
http://mxtoolbox.com/SuperTool.aspx?action=blacklist%3asmartfile.com&run=toolpage
You might also want to check an ip address here instead of the domain name if you have multiple ip addresses.
If you are listed on any blacklists, search for a way to request removal from their black list.
Domain Keys (Sending Problem)
If you have an easy way to set up Domain Keys, such as the Google hosted email method, it might be wise to set up domain keys. It shouldn’t be necessary for your email to be delivered.
Domain Verification (Receiving Problem)
If you are using Google for hosted email, you may need to make sure your domain is still verified in the Google Apps admin. Verification can be done by adding a DNS record, file on web-server, or header to page. If any of these mistakenly get removed, your domain can become unverified in Google and Google will stop processing emails.
Bounces (Sending Problem)
If you are getting bounced emails, determine why the email bounced.
- If the email bounced because the user is unknown, verify the email address or remove the user from your list. You might have been given an email that doesn’t exist. It is important to remove bad emails from your list, especially if using email service designed for commercial email.
- If the email bounced for other reasons, determine the reson from the bounced email.
Spam Filters (Sending Problem)
Try sending your email without fancy formating. Try removing images. It is also said that certain words trigger spam filters to raise the spam score. If you got a bounce, look at the headers of the email to determine if a spam score has been assigned.
I’ve found that it is best practice to add the following headers to email sent from applications:
Organization: [Company Name, example: SmartFile]X-Mailer: [Software that sent the email, examples: Django 1.4.18 powered by Python 2.7.2, PHP5.5.0RC3]X-Originating-IP: [User IP of website, exmaple: 93.184.216.34]
Share Your Comments
If the above checks are giving your fits or you would like to add another check, let us know in the comments.